UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

A comprehensive investigation of data dictionaries Diersch, Thomas Karl Julius 1982

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1982_A4_6 D54.pdf [ 5.44MB ]
Metadata
JSON: 831-1.0095447.json
JSON-LD: 831-1.0095447-ld.json
RDF/XML (Pretty): 831-1.0095447-rdf.xml
RDF/JSON: 831-1.0095447-rdf.json
Turtle: 831-1.0095447-turtle.txt
N-Triples: 831-1.0095447-rdf-ntriples.txt
Original Record: 831-1.0095447-source.json
Full Text
831-1.0095447-fulltext.txt
Citation
831-1.0095447.ris

Full Text

COMPREHENSIVE INVESTIGATION OF DATA DICTIONARIES BY THOMAS KARL JULIUS DIERSCH B . S c , The U n i v e r s i t y of B r i t i s h C o lumbia, 1975 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN BUSINESS ADMINISTRATION IN THE FACULTY OF GRADUATE STUDIES (COMMERCE AND BUSINESS ADMINISTRATION) WE ACCEPT THIS THESIS AS CONFORMING TO THE REQUIRED STANDARD: THE UNIVERSITY OF BRITISH COLUMBIA APRIL 1982 © T h o m a s K a r l J u l i u s D i e r s c h , 1982 I n p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t o f t h e r e q u i r e m e n t s f o r an a d v a n c e d d e g r e e a t t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a , I a g r e e t h a t t h e L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and s t u d y . I f u r t h e r a g r e e t h a t p e r m i s s i o n f o r e x t e n s i v e c o p y i n g o f t h i s t h e s i s f o r s c h o l a r l y p u r p o s e s may be g r a n t e d by t h e h e a d o f my d e p a r t m e n t o r by h i s o r h e r r e p r e s e n t a t i v e s . I t i s u n d e r s t o o d t h a t c o p y i n g o r p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l n o t be a l l o w e d w i t h o u t my w r i t t e n p e r m i s s i o n . D e p a r t m e n t o f The U n i v e r s i t y o f B r i t i s h C o l u m b i a 1956 Main Mall V a n c o u v e r , Canada V6T 1Y3 DE-6 (3/81) ABSTRACT T h i s t h e s i s r e v i e w s d a t a d i c t i o n a r y s y s t e m s , a p p r o a c h i n g t h e s u b j e c t from f o u r d i r e c t i o n s . . F i r s t , t h e c o n t e n t s o f d i c -t i o n a r i e s a r e exa m i n e d . Second, t h e u s e r s and t h e i r i n t e r a c -t i o n and use of t h e d a t a d i c t i o n a r y a r e r e v i e w e d . T h i r d , some p o p u l a r c o m m e r c i a l d a t a d i c t i o n a r y p a c k a g e s a r e r e v i e w e d . F i n a l l y , d a t a d i c t i o n a r i e s a r e examined a s a pa c k a g e t o be imp l e m e n t e d by a d a t a p r o c e s s i n g d e p a r t m e n t . D a t a d i c t i o n a r y e n t i t i e s c a n be g r o u p e d i n t o f o u r c l a s s e s , e a c h a d d i n g t o t h e i n f o r m a t i o n s t o r e d by t h e p r e c e e -d i n g l a y e r . They a r e , t h e d a t a d i c t i o n a r y w h i c h s t o r e s d a t a e n t i t y d a t a , d a t a d i r e c t o r i e s , w h i c h s t o r e p r o c e s s i n g e n t i t y d a t a and p r o c e s s - d a t a r e l a t i o n s h i p s , d a t a r e s o u r c e d i c -t i o n a r i e s , w h i c h s t o r e d a t a a b o u t p r o c e s s i n g e n v i r o n m e n t e n t i -t i e s s u c h a s h a r d w a r e , and t h e m e t a d a t a d i c t i o n a r y w h i c h s t o r e s d a t a a b o u t c o n c e p t u a l e n t i t i e s s u c h a s e v e n t s and f u n c -t i o n s . U s i n g t h i s s t r u c t u r e , e a c h c l a s s of d i c t i o n a r y i s e x a -mined t o i d e n t i f y t h e e n t i t i e s and t h e i r a t t r i b u t e s . U s e r s a r e examined i n t h e f o l l o w i n g g r o u p s : t h e d a t a b a s e a d m i n i s t r a t o r , s y s t e m s a n a l y s t s , programmers, t h e d a t a p r o c e s -s i n g o p e r a t i o n s d e p a r t m e n t , and t h e u s e r g r o u p . F i v e c o m m e r c i a l l y a v a i l a b l e d i c t i o n a r i e s a r e examined i n d e t a i l , DATAMANAGER, DB/DC D a t a D i c t i o n a r y , D a t a C a t a l o g u e 2, UCC-10, and IDD. In a d d i t i o n , t h e t h e s i s e xamines two d i e -t i o n a r i e s i n o v e r v i e w , h i g h l i g h t i n g t h e i r a d v a n c e d t h i n k i n g . I C L DDS, w h i c h a l l o w s t h e u s e r t o model b o t h i m p l e m e n t a t i o n and c o n c e p t u a l v i e w s o f d a t a , and CINCOM's DCS wh i c h i n c l u d e s t h e d i c t i o n a r y i n a p a c k a g e c o n t a i n i n g a s c r e e n d e s i g n a i d , a programmer w o r k s t a t i o n , and s e c u r i t y s y s t e m a l l i n t e g r a t e d w i t h t h e d i c t i o n a r y . The d a t a d i c t i o n a r y i s examined from a s y s t e m a p p l i c a t i o n v iew p o i n t a d d r e s s i n g t h e q u e s t i o n s t o w h i c h any a p p l i c a t i o n i s s u b j e c t e d when e v a l u a t e d . I d e n t i f y i n g t h e need f o r a d a t a d i c t i o n a r y , t h r e e a r e a s a r e examined. F i r s t t h e c o n t r o l of d a t a as an o r g a n i z a t i o n a l r e s o u r c e , s e c o n d t h e use of s y s t e m d e v e l o p m e n t m e t h o d o l o g i e s and t h i r d , t h e management of change i n d a t a p r o c e s s i n g s y s t e m s . The a b i l i t y o f t h e d a t a d i c t i o n a r y t o s u p p o r t a d a t a p r o -c e s s i n g e n v i r o n m e n t w h i c h u s e s c o n v e n t i o n a l f i l e s t r u c t u r e s , a s i m p l e d a t a b a s e o r a complex e n v i r o n m e n t w i t h m u l t i p l e d a t a -b a s e s , o r d i s t r i b u t e d p r o c e s s i n g i s a d d r e s s e d . S o f t w a r e s e l e c t i o n c r i t e r i a a r e examined, d e f i n i n g t h e d i c t i o n a r y c o n t e n t , and u t i l i t i e s w h i c h s h o u l d be i n v e s t i -g a t e d , and c r i t e r i a f o r e n v i r o n m e n t s u c h a s d a t a p r o c e s s i n g h a r d w a r e and s o f t w a r e , u s e r - v e n d o r r e l a t i o n s h i p s and c o s t and m a i n t e n a n c e a r e p r o p o s e d , F i n a l l y we p r o p o s e some e v e n t s i n t h e d a t a p r o c e s s i n g l i f e c y c l e w h i c h may a s s i s t i n t h e s u c e s s f u l i m p l e m e n t a t i o n o f a d a t a d i c t i o n a r y . I m p l e m e n t a t i o n i n a complex e n v i r o n m e n t i v where no o t h e r p r o j e c t p r o p o s e d i s c r i t i c a l , or b e f o r e a major d a t a b a s e management s y s t e m c o n v e r s i o n may be w a r r a n t e d . Or i m p l e m e n t a t i o n may be u n d e r t a k e n b e f o r e a l a r g e s y s t e m s p r o -j e c t , o r as p a r t of a d a t a p r o c e s s i n g s t a n d a r d s p r o j e c t . V TABLE OF CONTENTS PAGE CHAPTER 1 • INTRODUCTION 1 1 .1 O b j e c t i v e s 2 1.2 Chapter Synopses 3 CHAPTER 2 « CLASSES OF DATA DICTIONARIES 5 2.1 Data D i c t i o n a r y 9 2.2 Data D i r e c t o r y 21 2.3 Data Resource D i c t i o n a r y 27 2.4 Metadata D i c t i o n a r y 34 CHAPTER 3 • USERS OF THE DATA DICTIONARY 37 3.1 The Data Base A d m i n i s t r a t o r 38 3.2 The Systems A n a l y s t 46 3.3 The Programmer 50 3.4 The O p e r a t i o n s Department 52 3.5 The User Group 54 CHAPTER 4 • SURVEY OF COMMERCIAL DATA DICTIONARIES 57 4 i 1 Datamanager 60 4.2 DB/DC Data D i c t i o n a r y 64 4.3 Data C a t a l o g u e 2 68 4.4 UCC-1 0 72 4.5 IDD 77 CHAPTER 5 • A DATA DICTIONARY IN AN ENTERPRISE ENVIRONMENT 92 5.1 The Need For A Data D i c t i o n a r y 94 5.2 So f t w a r e S e l e c t i o n 112 5.3 Implementation 127 CHAPTER 6 • CONCLUSION 135 BIBLIOGRAPHY • 141 v i L I S T OF TABLES PAGE T a b l e I ® I n f o r m a t i o n S o u r c e s -- D a t a D i c t i o n a r y P a c k a g e s v i i LIST OF FIGURES PAGE F i g u r e 1 • Data D i c t i o n a r y Model 6 F i g u r e 2 • Data D i c t i o n a r y F u n c t i o n s 39 F i g u r e 3 • F u n c t i o n M a t r i x 48 F i g u r e 4 • I n f o r m a t i o n Flow Diagram 49 F i g u r e 5 • Data For A n a l y s i s — S t o r e d By The Data D i c t i o n a r y 101 F i g u r e 6 • Data D i c t i o n a r y In A C o n v e n t i o n a l Environment 105 F i g u r e 7 • Data D i c t i o n a r y D u r i n g A DBMS I n s t a l l a t i o n ... 107 v i i i ACKNOWLEDGEMENT I would l i k e t o r e c o g n i z e those i n d i v i d u a l s who have a s s i s t e d me i n the c o m p l e t i o n of t h i s work. Foremost., I thank my w i f e , E i l e e n , who has s u p p o r t e d and encouraged me t h r o u g h o u t . Without h e r , t h i s work would not have been completed. I would a l s o l i k e t o thank my committee, Robert C. G o l d s t e i n , my ad-v i s o r , A l b e r t S. D e x t e r , and A l v i n F o w l e r . T h e i r e f f o r t and a s s i s t a n c e a re v e r y much a p p r e c i a t e d , e s p e c i a l l y i n l i g h t of the d i f f i c u l t i e s I had i n c o m p l e t i n g the work. F i n a l l y , I would l i k e t o thank A r t h u r Andersen & Co. f o r a l l o w i n g me the time t o complete t h i s t h e s i s . CHAPTER 1 1 INTRODUCTION The d a t a d i c t i o n a r y i s a s o f t w a r e t o o l u s e d by an e n t e r -p r i s e t o c o n t r o l t h e d a t a i t u s e s . The c o n t r o l o f d a t a i s i m p o r t a n t t o o r g a n i z a t i o n s w h i c h have grown s u f f i c i e n t l y l a r g e and complex t h a t i t i s no l o n g e r e a s y f o r management t o o b t a i n i n f o r m a t i o n from i t s o r g a n i z a t i o n a l u n i t s w i t h o u t f o r m a l p r o -c e d u r e s . O r g a n i z a t i o n s have r e s p o n d e d t o t h e need f o r i n f o r -m a t i o n by c r e a t i n g more complex d a t a g a t h e r i n g mechanisms. The s t a t e of t h e a r t i n s u c h mechanisms i n c l u d e d a t a e n t r y i n t o a computer s y s t e m a t t h e s o u r c e o f d a t a c r e a t i o n , f o l -l owed by i t s s t o r a g e u s i n g a r i g i d s t r u c t u r e f o r m a t i n a d a t a -base management s y s t e m (DBMS). In a c h i e v i n g t h i s l e v e l o f d a t a management, the need t o d e s c r i b e a l l d a t a , and a t t r i b u t e s o f t h e d a t a , s u c h as s t o r a g e , l o c a t i o n , f o r m a t , u s e s , and s o u r c e s , has n e c e s s i t a t e d d e v e l o p m e n t a l work i n t h e s t r u c t u r e , c o n t e n t and f o r m a t o f m e t a d a t a d i c t i o n a r i e s . 1 S e v e r a l c o m m e r c i a l p r o d u c t s a r e a v a i l a b l e under t h e g e n e r i c t i t l e o f d a t a d i c t i o n a r i e s . 1 M e t a d a t a i s a term u s e d t o i n d i c a t e t h a t t h e d a t a i s a t a h i g h e r o r meta l e v e l . An o r g a n i z a t i o n ' s d a t a c a n be d e s c r i b e d by i t s m e t a d a t a d e f i n i t i o n . M e t a d a t a i s t h e r e f o r e , d a t a a b o u t d a t a . 2 1.1 O b j e c t i v e s T h i s p a p e r has t h e f o l l o w i n g o b j e c t i v e s : 1. To d e f i n e t h e s c o p e of a d a t a d i c t i o n a r y i n terms o f i t s c o n t e n t , f u n c t i o n s p e r f o r m e d and i n d i v i d u a l s o r g r o u p s w h i c h b e n e f i t f r o m i t s e x i s t e n c e . 2 . To summarize t h e f i n d i n g s o f a number o f p u b l i c a t i o n s w h i c h have e v a l u a t e d t h e c o m m e r c i a l d a t a d i c t i o n a r y p a c -kages a v a i l a b l e . 3 . To examine t h e r o l e t h e d a t a d i c t i o n a r y p l a y s i n an en-t e r p r i s e e n v i r o n m e n t , s u p p o r t i n g t h e t e c h n i c a l c o m p l e x i -t y of t o d a y ' s i n f o r m a t i o n s y s t e m s . 4. To examine t h e major s e l e c t i o n c r i t e r i a w h i c h a r e c o n s i -d e r e d when c h o o s i n g a d a t a d i c t i o n a r y p a c k a g e . 5. To p r e s e n t t h o s e i n s t a n c e s when the i m p l e m e n t a t i o n of a d a t a d i c t i o n a r y package i s l i k e l y t o meet w i t h s u c c e s s . 3 1 .2 C h a p t e r S y n o p s e s T h i s p a p e r e x a m i n e s t h e d a t a d i c t i o n a r y from f o u r v i e w s : 1. C l a s s i f y i n g t h e d a t a d i c t i o n a r y b a s e d on i n f o r m a t i o n s t o r e d and f a c i l i t i e s a v a i l a b l e t o r e t r i e v e and manipu-l a t e t h e d a t a . The f o u r c l a s s e s a r e : a) d a t a d i c t i o n a r i e s w h i c h s t o r e b a s i c i n f o r m a t i o n a b o u t d a t a e l e m e n t s , b) d a t a d i r e c t o r i e s w h i c h i d e n t i f y l o c a t i o n o f d a t a s t o r e d , c ) d a t a r e s o u r c e d i c t i o n a r i e s w h i c h c o n t a i n i n f o r m a t i o n a b o u t p r o g r a m s , s y s t e m s , f i l e s and d a t a b a s e s as w e l l a s d a t a e l e m e n t s , and d) m e t a d a t a d i c t i o n a r i e s w h i c h c o n t a i n i n f o r m a t i o n a b o u t c o n c e p t u a l d a t a v i e w s w h i c h may o r may not be i m p l e -mented i n computer o r manual i n f o r m a t i o n p r o c e s s i n g s y s t e m s . 2. E x a m i n i n g t h e impact of t h e d a t a d i c t i o n a r y s y s t e m one c l a s s e s u s e r s o f t h e d i c t i o n a r y i n an e n t e r p r i s e : a) The d a t a b a s e a d m i n i s t r a t o r and d a t a p r o c e s s i n g mana-gement who s u p p l y i n f o r m a t i o n and e n s u r e i t s c o r r e c t -n e s s and c o m p l e t e n e s s b) The t r a n s f o r m e r s o f d a t a i n t o i n f o r m a t i o n ( e . g . s y s t e m a n a l y s t s , programmers and computer o p e r a t o r s ) who t r a n s l a t e u s e r s ' d e s i r e s f o r i n f o r m a t i o n i n t o 4 a u t o m a t e d d a t a m a n i p u l a t i o n p r o c e s s e s c) The end u s e r s f o r whom d a t a i s a t o o l i n t h e p e r f o r -mance o f a t a s k . 3. R e v i e w i n g d a t a d i c t i o n a r i e s a v a i l a b l e a s p a c k a g e d s o f t -ware. T h i s e x a m i n a t i o n w i l l c o v e r t h e most p o p u l a r s y s -tems and i d e n t i f y t h e i r common and u n i q u e c h a r a c t e r i s -t i c s . 4. E v a l u a t i n g t h e d a t a d i c t i o n a r y a s an a d d i t i o n a l a p p l i c a -t i o n managed by t h e d a t a p r o c e s s i n g d e p a r t m e n t . T h i s s e c t i o n w i l l d e a l w i t h t h e i s s u e s o f : a) i d e n t i f y i n g t h e need f o r a d a t a d i c t i o n a r y t o s u p p o r t t h e i n f o r m a t i o n p r o c e s s i n g t a s k , b) c r i t e r i a u s e d t o s e l e c t a s u i t a b l e d a t a d i c t i o n a r y s y s t e m , and c) g u i d e l i n e s f o r t h e i m p l e m e n t a t i o n of a d a t a d i c -t i o n a r y s y s t e m . The f i n a l c h a p t e r w i l l examine f u t u r e t r e n d s f o r d a t a d i c t i o n a r i e s . Two i s s u e s w i l l be a d d r e s s e d : 1. The p l a c e of a d a t a d i c t i o n a r y s y s t e m i n t h e d a t a p r o -c e s s i n g e n v i r o n m e n t . 2. The impact d a t a management s y s t e m s w i l l have on t h e de-v e l o p m e n t and use of d a t a d i c t i o n a r y s y s t e m s . 5 CHAPTER 2 CLASSES OF DATA DICTIONARIES Overview Packages t h a t document d a t a about d a t a , or l i t e r a t u r e t h a t d e s c r i b e s such d a t a , use naming c o n v e n t i o n s which l e a v e the r e a d e r c o n f u s e d about the o b j e c t d e s c r i b e d . 2 T h i s paper proposes f o u r c l a s s i f i c a t i o n s t o d e s c r i b e s o f t w a r e d e s c r i p -t i o n s i n the l i t e r a t u r e and packages which are a v a i l a b l e . T h i s model (see F i g u r e 1) can be thought of as a l a y e r e d c y l -i n d e r where each s u c c e s s i v e l a y e r i s a more complex, more com-p l e t e d e s c r i p t i o n of e n t e r p r i s e e n t i t i e s . 3 Each s u c c e e d i n g l a y e r c o n t a i n s the i n f o r m a t i o n of the p r e c e e d i n g l a y e r . These l a y e r s a r e : 1. A d a t a d i c t i o n a r y . T h i s l a y e r c o n t a i n s the d e s c r i p t i o n of d a t a e n t i t i e s . These d a t a e n t i t e s a r e d e s c r i b e d 2 P. P. U h rowczik, "Data D i c t i o n a r y / D i r e c t o r i e s , " IBM Systems  J o u r n a l , 12 (1973),332-350 ,-George M a r t i n , "Data D i c t i o n a r y / D i r e c t o r y System," J o u r n a l of Systems Management, 24 (Dec. 1973), 12-19; S. J . Waters, "Towards Comprehensive S p e c i f i c a t i o n s , " Computer J o u r n a l , 22 (Aug. 1979), 195-199. 3 An e n t i t y i s a p e r s o n , p l a c e , t h i n g , concept or e v e n t , r e a l or a b s t r a c t , of i n t e r e s t t o the e n t e r p r i z e . ANSI/SPARC/X3 Study Group on Data Base Management Systems, "Interm R e p o r t , " FDT, 7,No. 2 (1975), 18. F i g u r e 1 Data D i c t i o n a r y Model 7 i n terms of i n t r i n s i c a t t r i b u t e s such as f o r m a t , s i z e , and name. 2. A d a t a d i r e c t o r y . The d a t a d i r e c t o r y c o n t a i n s a d d i -t i o n a l d a t a e n t i t y a t t r i b u t e s such as l o c a t i o n , use, and s t r u c t u r e . * The d a t a d i r e c t o r y a l s o d e s c r i b e s p r o c e s s e n t i t i e s such as programs, modules and systems and e s t a -b l i s h e s r e l a t i o n s h i p s between d a t a and p r o c e s s i n g e n t i -t i e s . 3. A d a t a r e s o u r c e d i c t i o n a r y . The d a t a r e s o u r c e d i c -t i o n a r y c o n t a i n s i n f o r m a t i o n not o n l y about data and p r o c e s s i n g e n t i t i e s , but a l s o about environment e n t i t i e s such as hardware p r o c e s s o r s , p h y s i c a l d a t a f i l e s , and d i s t r i b u t e d database systems. 4. The metadata d i c t i o n a r y . T h i s l e v e l adds i n f o r m a t i o n c o n c e r n i n g c o n c e p t u a l e n t i t i e s such as e v e n t s and f u n c -t i o n s , o r g a n i z a t i o n a l e n t i t i e s , and t h e i r a t t r i b u t e s . 5 The e n t i t i e s documented are not n e c e s s a r i l y implemented i n a computer system. * A s t r u c t u r e i s a c o l l e c t i o n of z e r o or more o b j e c t s connected by a d i r e c t e d r e l a t i o n s h i p . I b i d . , p.17. 5 An a t t r i b u t e i s the r e p r e s e n t a t i o n of a p r o p e r t y of an e n t i t y . I b i d . , p.16. I t i s the s e t of v a l u e s which a c h a r a c t e r i s t i c of an e n t i t y may take on. 8 W i t h t h e e x c e p t i o n of t h e m e t a d a t a d i c t i o n a r y , an e n t e r -p r i s e c o u l d have one o r more d a t a r e s o u r c e d i c t i o n a r i e s ( w h i c h i n c l u d e s t h e i n f o r m a t i o n c o n t a i n e d i n t h e d a t a d i c t i o n a r y and d i r e c t o r y ) , d e p e n d i n g on t h e number o f f u n c t i o n a l a r e a s w h i c h a r e d e s c r i b e d . Thus, i f an e n t e r p r i s e c o n s i s t s of s e v e r a l d i s t i n c t f u n c t i o n a l a r e a s , e a c h c o u l d have t h e i r own d a t a r e -s o u r c e d i c t i o n a r y . A m e t a d a t a d i c t i o n a r y , however, d e s c r i b e s t h e e n t i r e e n t e r p r i s e , and a l t h o u g h i t may be r e p r o d u c e d , e x i s t s u n i q u e l y . E n t r y P o i n t s R e g a r d l e s s of t h e t y p e o r amount of i n f o r m a t i o n s t o r e d by th e d a t a d i c t i o n a r y s y s t e m , t h r e e e n t r y p o i n t s a r e r e q u i r e d t o r e t r i e v e i n f o r m a t i o n : 1. T h r o u g h a s u b j e c t - o r i e n t e d keyword o r keyword p h r a s e . Such keywords a r e d e f i n e d by t h e u s e r and a l l o w f o r b r o w s i n g . The keyword i s an a t t r i b u t e of t h e e n t i t y and t h e word or p h r a s e u s e d i n i n q u i r y a r e t h e v a l u e s of t h e a t t r i b u t e . 2 . T h r o u g h a u n i q u e d a t a name. T h i s name may be e i t h e r u s e r o r s y s t e m a s s i g n e d . R e t r i e v a l by t h i s method s h o u l d r e t u r n a l i m i t e d amount of i n f o r m a t i o n i n a p r e -d e f i n e d f o r m a t . T h i s a c c e s s method would a l l o w f o r r e -9 t r i e v a l of i n f o r m a t i o n by programs or o t h e r s o f t w a r e systems. 3. By u s i n g v a l u e s of e n t i t y a t t r i b u t e s or names of e n t i t y t y p e s . For example, the "name-synonym" as an a t t r i b u t e of a d a t a e n t i t y , or a s p e c i f i c e n t i t y type such as " f i l e " . T h i s type of s e a r c h would a l l o w f o r the d e s c r i -p t i o n of an e n t i t y such as a program or a f i l e i n terms of the a t t r i b u t e s s t o r e d and would i d e n t i f y c r o s s - r e -f e r e n c e s t o o t h e r e n t i t i e s . A s e a r c h statement such a s : FILE = EMPLOYEE... where a l l f i l e s b e g i n n i n g w i t h EMPLOYEE are i d e n t i f i e d . Such i n f o r m a t i o n would most l i k e l y be used by the Data Base A d m i n i s t r a t o r (DBA) and o t h e r d a t a p r o c e s s i n g p e r -s o n n e l such as system a n a l y s t s and programmers who are i n t e r e s t e d i n a g e n e r i c i n f o r m a t i o n c o n c e r n i n g the type of i n f o r m a t i o n s t o r e d . 2 . 1 Data D i e t i o n a r y E n t i t i e s d e s c r i b e d by the da t a d i c t i o n a r y a re concerned w i t h d a t a or d a t a s t r u c t u r e s . The auth o r proposes f i v e d i s -t i n c t d a t a e n t i t i e s . They a r e el e m e n t s , d a t a groups, p h y s i c a l segments, f i l e s , and d a t a b a s e s . The s m a l l e s t independent u n i t of d a t a d e s c r i b e d i n a dat a d i c t i o n a r y i s the element, a l s o c a l l e d a f i e l d or an item 10 i n t h e l i t e r a t u r e . The m a j o r i t y o f t h e a t t r i b u t e s m a i n t a i n e d by t h e d a t a d i c t i o n a r y a r e u s e d t o d e s c r i b e t h i s u n i t of d a t a . The n e x t most complex d a t a e n t i t y i s t h e d a t a g r o u p . A d a t a g r o u p i s a l o g i c a l l y r e l a t e d g r o u p of e l e m e n t s combined f o r c o n v e n i e n c e . An example of a d a t a g r o u p i s TODAYS-DATE w h i c h c o n s i s t s of t h e e l e m e n t s DAY, MONTH and YEAR. The g r o u p , TODAYS-DATE, i s combi n e d p u r e l y o u t of c o n v e n i e n c e and i s d e s -c r i b e d f u l l y by t h e a t t r i b u t e s w h i c h d e s c r i b e t h e d a t a e l e -ment . The p h y s i c a l segment, a l s o known as a r e t r i e v e d r e c o r d , i s an e n t i t y w h i c h d e s c r i b e s t h e s m a l l e s t u n i t of a c c e s s i b l e d a t a on a p h y s i c a l s t o r a g e d e v i c e . T h i s e n t i t y has a d d i t i o n a l a t t r i b u t e s n ot a p p l i c a b l e t o e l e m e n t s . T h e s e a t t r i b u t e s , s u c h as key, i d e n t i f y t h e p h y s i c a l segment as a r e q u i r e d e n t i t y i n th e d a t a c l a s s i f i c a t i o n h i e r a r c h y . G r o u p i n g p h y s i c a l segments one can c r e a t e d a t a s e t s or f i l e s . In a f i l e , a l l members need not be a l i k e , t h e r e f o r e a t t r i b u t e s s u c h as h e a d e r , t r a i l e r o r " m u l t i p l e o c c u r r i n g " need t o be u s e d t o i d e n t i f y e a c h member o f a f i l e . The most complex d a t a c o n s t r u c t i s t h e d a t a b a s e . A d a t a -b a s e i s a s e t of r e c o r d s , g r o u p s , o r e l e m e n t s w h i c h have i n common t h e i r use by one o r more b u s i n e s s f u n c t i o n a l e n t i t i e s , and w h i c h a r e d e s c r i b e d i n a s t r u c t u r e d f o r m a t . The b u s i n e s s f u n c t i o n a l e n t i t y i s a s u b u n i t o f t h e e n t e r p r i s e w h i c h c a r r i e s o u t a p a r t i c u l a r b u s i n e s s f u n c t i o n . E x a mples of a b u s i n e s s 11 f u n c t i o n a r e p a y r o l l c a l c u l a t i o n , and p u r c h a s i n g of raw ma-t e r i a l s . Data D i e t i o n a r y C o n t e n t s As we have proposed, the m a j o r i t y of the d a t a d i c t i o n a r y documentation i s i n f o r m a t i o n about d a t a e l ements. As such, the m a j o r i t y of d a t a e n t i t y a t t r i b u t e s a p p l y o n l y t o the e l e -ment. T h i s d i s c u s s i o n w i l l d e a l w i t h g e n e r a l e n t i t y a t t r i -b utes and i d e n t i f y those a t t r i b u t e s which a r e s p e c i f i c t o one e n t i t y t y p e . A t t r i b u t e s of d a t a e n t i t i e s can be grouped i n t o f i v e c l a s s e s : -1. Name i n f o r m a t i o n . T h i s would i n c l u d e any a t t r i b u t e i d e n t i f y i n g the e n t i t y . 2. Content i n f o r m a t i o n . T h i s i n c l u d e s a t e x t u a l d e s c r i p -t i o n and would d i s t i n g u i s h the e n t i t y from any s i m i l a r l y named e n t i t i e s . 3. S t r u c t u r e i n f o r m a t i o n . T h i s would i n c l u d e i n f o r m a t i o n c o n c e r n i n g , the o r d e r i n g or o r g a n i z a t i o n of the element i n more complex s t r u c t u r e s such as groups, p h y s i c a l seg-ments, f i l e s , and d a t a b a s e s . Examples a r e key, i n d e x , and sequence. T h i s i n f o r m a t i o n i s commonly s t o r e d a t the group, segment, f i l e , or database l e v e l , t h r o u g h an 12 a t t r i b u t e or named r e l a t i o n s h i p " c o n t a i n s " , i d e n t i f y i n g a lower l e v e l e n t i t y o c c u r r e n c e as the members con-t a i n e d . However, i t c o u l d be r e p r e s e n t e d a t the lower l e v e l ( i n c l u d i n g element) by a named r e l a t i o n s h i p " o c c u r s - i n " , which would i d e n t i f y those h i g h e r l e v e l e n t i t y o c c u r r e n c e s where i t would be a member. 4. I n t e g r i t y i n f o r m a t i o n . T h i s would i n c l u d e a t t r i b u t e s which would be used t o t e s t f o r the c o r r e c t d e s c r i p t i o n of the element. Such i n f o r m a t i o n would i n c l u d e l e n g t h , p i c t u r e v a l u e s , e d i t r u l e s , and c l a s s i f i c a t i o n s . 5 . P r i v a c y and s e c u r i t y i n f o r m a t i o n . T h i s d a t a would i n c -lude a t t r i b u t e s such as c r e a t i o n and m o d i f i c a t i o n au-t h o r i z a t i o n , i n f o r m a t i o n d i s s e m i n a t i o n , and a l l o w e d usage which would p e r m i t the document i o n of p r i v a c y and s e c u r i t y l e v e l s of da t a e n t i t i e s . Name A t t r i b u t e s Name a t t r i b u t e s a r e im p o r t a n t i n i d e n t i f y i n g each o c c u r -rence of a d a t a e n t i t y . Major a t t r i b u t e s h e l d i n the d i c -t i o n a r y a r e : 1. L a b e l or i d e n t i f i e r i n f o r m a t i o n . T h i s may be a name or system i d e n t i f i e r which p r o v i d e s a unique key f o r each 1 3 e n t i t y o c c u r r e n c e . 2. A d e s i g n a t o r , one or more key words which a r e used as a s e a r c h p a t h i n i d e n t i f y i n g a p a r t i c u l a r e n t i t y o c c u r -rence 3. Synonyms f o r the l a b e l , d e s c r i b i n g commonly used i d e n t i -f i e r s r e l a t e d t o systems, programs or user f u n c t i o n s . 4. Language synonyms such as COBOL or PL/1 names i n c l u d e d t o i d e n t i f y the commonly used name w i t h i n a computer program. Content A t t r i b u t e s Content i n f o r m a t i o n c o n s i s t s of d e s c r i p t i o n a t t r i b u t e s which may be used i n documentation or user u n d e r s t a n d i n g of the e n t i t y o c c u r r e n c e . Common a t t r i b u t e s a r e : 1. The t e x t u a l d e s c r i p t i o n of the e n t i t y o c c u r r e n c e . T h i s i s a f r e e format a l p h a n u m e r i c d e s c r i p t i o n which may be used i n docu m e n t a t i o n . 2. S t a t u s i n f o r m a t i o n which the e n t i t y o c c u r r e n c e v a l u e s a r e : would i d e n t i f y the s t a t u s of d u r i n g i t s l i f e . Common s t a t u s 14 a) proposed - not y e t r e v i e w e d or c o m p l e t e l y d e f i n e d b) c o n c u r r e d - t h i s would i n d i c a t e a l l u s e r s and o t h e r a f f e c t e d persons had agreed t o the d e f i n i t i o n of the o c c u r r e n c e c) approved - t h i s would i d e n t i f y t h a t the prop e r appro-v a l f o r p l a c i n g the e n t i t y o c c u r r e n c e i n t o d a i l y use has been g i v e n by the proper a u t h o r i t y . At t h i s s t a g e a l l data n e c e s s a r y t o d e f i n e the e n t i t y o c c u r -rence has been e n t e r e d d) e f f e c t i v e - t h i s i d e n t i f i e s t h a t the e n t i t y o c c u r -rence i s p r e s e n t l y i n e f f e c t e) superseded - t h i s i d e n t i f i e s a p r e v i o u s o c c u r r e n c e of t h i s e n t i t y type 3. V e r s i o n i n f o r m a t i o n p r o v i d e s f o r more than one e f f e c t i v e e n t i t y o c c u r r e n c e w i t h the same i d e n t i f i e r i n the system a t one t i m e . T h i s may be n e c e s s a r y when a l t e r n a t i v e or t e s t d a t a e n t i t y o c c u r e n c e s a r e d e s i r e d , as i n the d e s i g n of a da t a b a s e . 4. In o r d e r t o f u r t h e r d e s c r i b e the e n t i t y o c c u r r e n c e , i t i s sometimes u s e f u l t o i d e n t i f y a u n i t of measure. T h i s would i n d i c a t e , f o r example, t h a t an element named TOTAL-EARNINGS has a u n i t of measure, d o l l a r s . And an element TOTAL-EARNINGS-GB has a u n i t of measure, pounds s t e r l i n g . 1 5 S t r u c t u r e A t t r i b u t e s S t r u c t u r e a t t r i b u t e s a r e u s e d t o g r o u p l o w e r e n t i t i e s i n t o t h o s e o f a h i g h e r t y p e ( e . g . e l e m e n t s i n t o g r o u p s , phy-s i c a l segments , f i l e s and d a t a b a s e s ) , o r show t h e membership of l o w e r e n t i t i e s i n h i g h e r e n t i t i e s . A t t r i b u t e s u s e d i n de-f i n i n g t h e s t r u c t u r e i n c l u d e : 1. A key w h i c h i d e n t i f i e s t h e e l e m e n t o r e l e m e n t s w h i c h p r o v i d e a key sequence f o r t h e s t r u c t u r e . Keys may be s i n g l e , c o m p o s i t e , or a l t e r n a t e . 2. The s e q u e n c e of e l e m e n t s i n r e c o r d s or r e c o r d s i n f i l e s . T h i s a t t r i b u t e w o u l d i n c l u d e i n f o r m a t i o n t o a l l o w s p e c i -f i c r e c o r d f o r m a t s t o be r e c o n s t r u c t e d . 3. The o r g a n i z a t i o n of s t r u c t u r e s . T h i s would i n c l u d e i n -f o r m a t i o n on p h y s i c a l r e c o r d , f i l e , o r d a t a b a s e o r g a n i -z a t i o n , and would i n c l u d e v a l u e s s u c h as h i e r a r c h i c a l , HISAM, and ISAM. 4. The s o r t s e q u e n c e of t h e d a t a e n t i t y . T h i s may be t h e same a s t h e key, o r a d d i t i o n a l s o r t f i e l d s may be u s e d . T h i s a t t r i b u t e c o u l d a l s o o c c u r m u l t i p l y d e p e n d i n g on s y s t e m r e q u i r e m e n t s . 1 6 I n t e g r i t y A t t r i b u t e s I n t e g r i t y a t t r i b u t e s a l l o w f o r v a l i d a t i o n and c o n t e n t c h e c k i n g s u b r o u t i n e s t o be used t o ensure d a t a c o r r e c t n e s s on i n p u t . These a t t r i b u t e s a p p l y p r i m a r i l y t o the d a t a element. 1. The c h a r a c t e r s e t used. T h i s can have v a l u e s such as a l p h a , numeric, or g r a p h i c c h a r a c t e r . 2. The l e n g t h of the element i n c h a r a c t e r s , b y t e s or words. 3. The mode of th'e element. That i s , whether i t i s a b i t s t r i n g , a c h a r a c t e r , packed d e c i m a l , or i n ASCII or EBCDIC. 4. The p r e c i s i o n or number of s i g n i f i c a n t d i g i t s which a r e c a r r i e d w i t h t h i s element. 5. The j u s t i f i c a t i o n , whether l e f t or r i g h t , of t h i s e l e -ment. 6. The p i c t u r e of the element. N o r m a l l y a COBOL p i c t u r e p h rase i s used (e.g. S999V99). 7. E d i t r u l e s which c o u l d a p p l y . T y p i c a l v a l u e s f o r t h i s a t t r i b u t e a r e whether the element i s a c o n s t a n t , whether i t i s r e q u i r e d or o p t i o n a l , the u s u a l v a l u e t h a t the 1 7 element has, the range of v a l u e s t h a t the element may c a r r y , and any e d i t masks t h a t may be a p p l i c a b l e . 8. The d e r i v a t i o n a l g o r i t h m used i n c r e a t i n g t h i s element. 9. The c l a s s i f i c a t i o n or c a t e g o r y under which t h i s element f a l l s . T h i s i s sometimes u s e f u l i n p r o v i d i n g a l t e r n a t e s e a r c h c r i t e r i a f o r u s e r s of the d i c t i o n a r y . C a t e g o r i e s a r e u s u a l l y s p e c i f i c . t o a c e r t a i n e n t e r p r i s e . T y p i c a l c a t e g o r i e s a r e name, i n v e n t o r y d e s c r i p t o r , p e r s o n n e l d e s c r i p t o r , a c c o u n t i n g v a l u e , c u r r e n c y . 10. The s t a t e s of the element. T h i s i n c l u d e s codes which the element may have. T h i s i s d i f f e r e n t from c o n s t a n t s or range of v a l u e s i n t h a t the s t a t e d e f i n e s a f i x e d number of v a l u e s t h a t the element o c c u r r e n c e may t a k e . A t y p i c a l example i s a l i s t of codes. S e c u r i t y And P r i v a c y A t t r i b u t e s S e c u r i t y and p r i v a c y a t t r i b u t e s i d e n t i f y s u f f i c i e n t i n -f o r m a t i o n t o ensure t h a t u n a u t h o r i z e d a c c e s s t o the e n t i t y can be p r e v e n t e d i f such a r o u t i n e i s implemented i n the s o f t w a r e , and t h a t o n l y those who are a u t h o r i z e d t o use the e n t i t y can be i d e n t i f i e d . T y p i c a l a t t r i b u t e s a r e : 18 1. P r i v a c y c o n s t r a i n t s such as who may see, use, or modify the e n t i t y o c c u r r e n c e . 2. S p e c i f i c a t i o n r e s p o n s i b i l i t y f o r the e n t i t y o c c u r r e n c e . That i s , the i n d i v i d u a l or f u n c t i o n a l a r e a which has r e s p o n s i b i l i t y f o r c r e a t i n g the d a t a d i c t i o n a r y d e f i n i -t i o n . 3. The c o n t e n t r e s p o n s i b i l i t y or the i n d i v i d u a l or f u n c t i o n r e s p o n s i b l e f o r p r o v i d i n g the v a l u e s f o r the a c t u a l e n t i t y o c c u r r e n c e . 4 . S e c u r i t y parameters n e c e s s a r y t o ensure o n l y a u t h o r i z e d u s e r s have a c c e s s t o t h i s e n t i t y o c c u r r e n c e . Such p a r a -meters-may i n c l u d e passwords. 5. The d i s t r i b u t i o n of r e p o r t s or o t h e r hard copy media which c o n t a i n the e n t i t y . A l t h o u g h the p r e c e d i n g d e s c r i p t i o n of a d a t a d i c t i o n a r y i n c l u d e s o n l y a r e s t r i c t e d number of a t t r i b u t e s commonly i n c -l u d e d i n s o f t w a r e which bears the name "data d i c t i o n a r y " , t h i s r e s t r i c t e d subset of d a t a can be used as a b a s i c d a t a d i c -t i o n a r y . U t i l i t i e s c o u l d be d e s i g n e d , based on t h i s i n f o r m a -t i o n , which would p r o v i d e a l a r g e amount of e x t r e m e l y u s e f u l i n f o r m a t i o n . T h i s k i n d of system need not r e q u i r e a l a r g e amount of 19 s o p h i s t i c a t e d s o f t w a r e t o m a i n t a i n . In f a c t , some d a t a d i c -t i o n a r y s y s t e m s a r e manual. They p r o v i d e s t a n d a r d documenta-t i o n w h i c h e n s u r e s t h a t a c o m p l e t e , c o n s i s t e n t r e c o r d of a l l d a t a e n t i t i e s i s m a i n t a i n e d . B e c a u se i t i s a t a r e l a t i v e l y low l e v e l of d e t a i l , t h i s r e c o r d i s a c h i e v a b l e w i t h a minimum of s y s t e m s e x p e r t i s e . O n l y t h e most b a s i c d a t a g a t h e r i n g and d o c u m e n t i n g s k i l l s a r e r e q u i r e d . In f a c t , t h i s t a s k i s b e s t c a r r i e d out by p e r s o n n e l i n t h e u s e r d e p a r t m e n t s , u s i n g g u i d e -l i n e s e s t a b l i s h e d by t h e DBA t o i d e n t i f y t h e l e v e l of d e f i n i -t i o n f o r e a c h d a t a e n t i t y . Once a l l t h e e l e m e n t s have been i d e n t i f i e d , c a t e g o r i e s o f s i m p l e d a t a e l e m e n t s can be r e c o g n i z e d . 6 D a t a g r o u p e d by f u n c t i o n o r use can a s s i s t i n t h i s c a t e g o r i z a t i o n . In t h i s t a s k , c r o s s - r e f e r e n c e s w h i c h a r e b a s e d on Key Word In C o n t e x t (KWIC), a r e f r e q u e n t l y p r e p a r e d . D a t a g r o u p s or s t r u c t u r e s a r e t h e f i r s t s t e p t o w a r d s c r e a t i n g a c o r p o r a t e d a t a m o d e l . Because a l l d a t a e n t i t i e s a r e documented i n a s i m i l a r manner, s t a n d a r d r o u t i n e s f o r i n p u t o r e d i t c a n be p r e p a r e d . T h i s r e q u i r e s o n l y a s m a l l base o f i n f o r m a t i o n w h i c h i n c l u d e s i n t e g r i t y a t t r i b u t e s . B e s i d e s r e d u c i n g t h e amount of s y s t e m d e v e l o p m e n t or programming e f f o r t t h r o u g h t h e use o f s t a n d a r d s u b - r o u t i n e s o r modules, i t a l s o p r o m o t e s t h e t e m p l a t e ap-6 M. A. H u f f e n b e r g e r , "The D e s i g n of D a t a E l e m e n t s : A D a t a Base P e r s p e c t i v e , " P r o c e e d i n g s of t h e Symposium on Management  of D a t a E l e m e n t s i n I n f o r m a t i o n P r o c e s s i n g T G a t h e r s b u r g , M a r y l a n d : n.p., 1.97577 p. 109. 20 p r o a c h t o s y s t e m s d e v e l o p m e n t . A f o r m a l m e t h o d o l o g y f o r s y s -tems d e v e l o p m e n t i s much e a s i e r t o e n f o r c e and m o n i t o r i n t h i s e n v i r o n m e n t . A f i n a l b e n e f i t of d o c u m e n t i n g d a t a e n t i t i e s i s i n promo-t i n g d a t a b a s e c o n c e p t s , p a r t i c u l a r l y d a t a s h a r i n g . D a t a i n -t e r c h a n g e i s f a c i l i t a t e d t h r o u g h t h e use o f common, e a s i l y r e a d a b l e and u s a b l e d a t a d e f i n i t i o n s . T h i s a l l o w s u s e r s i n d i v e r s e f u n c t i o n a l a r e a s t o have a common u n d e r s t a n d i n g o f t h e d a t a d e f i n i t i o n . T h r o u g h common d e f i n i t i o n s , t h e d e s i g n of d a t a s t r u c t u r e s w h i c h a r e s h a r e d i s a much more r e a l i z a b l e t a s k . One o f t h e l a r g e s t d r a w b a cks t o s h a r e d d a t a f i l e s r e s u l t s f r o m t h e p a r o c h i a l a t t i t u d e t h a t u s e r s have t o s h a r i n g d a t a . By i d e n t i f y i n g and a s s i g n i n g r e s p o n s i b i l i t y f o r e n t i t y d e f i n i -t i o n t o t h e u s e r , so t h a t i n t e g r i t y and c o n t r o l would be a t t h e u s e r l e v e l , some of t h e o b j e c t i o n s t h a t u s e r s n o r m a l l y have t o " f i d d l i n g w i t h my d a t a " s h o u l d be removed. A key d a t a b a s e c o n c e p t i s t h e i n d e p e n d e n c e o f d a t a from s i n g l e a p p l i c a t i o n s or s y s t e m s . Key p a r a m e t e r s n e c e s s a r y t o p r o v i d e t h i s i n d e p e n d e n c e a r e t h e i d e n t i f i c a t i o n o f e n c o d i n g schemes, s t o r a g e modes, c h a r a c t e r s e t s , l a b e l s o r i d e n t i f i e r s , t h e range of v a l u e s , and t h e p h y s i c a l f o r m a t o f t h e d a t a . B e c a u s e t h e d a t a d i c t i o n a r y c an r e c o r d a l l of t h e s e a t t r i -b u t e s , t h e t r a n s l a t i o n i n t o a d i f f e r e n t s e t of p a r a m e t e r s i s a much e a s i e r t a s k . 21 2.2 Data D i r e c t o r y The d a t a d i c t i o n a r y i s concerned w i t h the c o n t e n t , s t r u c -t u r e , i n t e g r i t y , and s e c u r i t y a t t r i b u t e s of d a t a e n t i t i e s ; -however, d a t a e x i s t s w i t h i n an environment of p r o c e s s e s and e v e n t s . The d a t a d i r e c t o r y i s the second l a y e r of d a t a i n f o r -m ation s o f t w a r e . The d a t a d i r e c t o r y documents the l o c a t i o n a l c h a r a c t e r i s t i c s of d a t a . T h i s n e c e s s i t a t e s the documentation of p r o c e s s e n t i t i e s , and r e l a t i o n s h i p s between d a t a and p r o -c e s s e n t i t i e s . E n t i t i e s which are used t o document l o c a t i o n a l c h a r a c -t e r i s t i c s of d a t a i d e n t i f y the a c c e s s or use of d a t a . 7 These e n t i t i e s i n c l u d e : 1. Programs (computer programs) and s u b s t r u c t u r e s such as modules and s u b r o u t i n e s . 2. U s e r s of d a t a , i n c l u d i n g those who accumulate m a n i p u l a t e and s t o r e i t . 3 . P r o c e d u r e s , which i n c l u d e s w r i t t e n and v e r b a l p r o c e d u r e s s p e c i f y i n g p r o s c r i b e d a c t i o n s performed on d a t a . R e l a t i o n s h i p s between d a t a and p r o c e s s e s a r e documented th r o u g h e n t i t i e s which a r e used i n i n f o r m a t i o n communication. 7 U h r o w c z i k , p . 3 3 7 . 22 These e n t i t i e s a r e r e f e r e d t o as "data i n t e r c h a n g e e n t i t i e s " . These c o n s t r u c t s i n c l u d e : 1. T r a n s a c t i o n s which i d e n t i f y unique o c c u r r e n c e s of d a t a items r e l a t i n g t o a p a r t i c u l a r e v ent. 2 . R e p o r t s which i d e n t i f y d a t a g a t h e r e d t o p r o v i d e i n f o r m a -t i o n t o a u s e r . 3. Documents which a c t as t r i g g e r s or i n i t i a t o r s f o r t r a n -s a c t i o n s and e v e n t s . Data i n t e r c h a n g e e n t i t i e s a r e imp o r t a n t because they i d e n t i f y a unique r e l a t i o n s h i p between d a t a and the u s e r s . Such e n t i t i e s c o u l d be i n c l u d e d i n the da t a d i c t i o n a r y as a s p e c i a l i n s t a n c e of a group, however they a l s o r e l a t e t o p r o -c e s s e s , and i d e n t i f y the a c t i v e n a t u r e of da t a i n t e r c h a n g e . One of the major b e n e f i t s of m a i n t a i n i n g p r o c e s s e n t i t i e s i s the a b i l i t y t o i d e n t i f y r e l a t i o n s h i p s between p r o c e s s e s and d a t a . Database management systems (DBMS) c o n t a i n a s t r u c t u r e of d a t a e n t i t i e s . I f one c o u l d i d e n t i f y the r e q u e s t s f o r d a t a from programs which i n t e r a c t w i t h the DBMS, one c o u l d a c h i e v e s i m i l a r documentation t o t h a t i n f o r m a t i o n c o n t a i n e d i n the d a t a d i r e c t o r y . However, the user has no means of q u e r y i n g the r e l a t i o n s h i p s between programs and the DBMS d a t a . That i s , t h e r e i s no system f a c i l i t y which a l l o w s the user t o i d e n -t i f y the u n d e r l y i n g p r o c e s s e s the programs s i m u l a t e . On the 23 o t h e r hand, the d a t a d i r e c t o r y c o n t a i n s d a t a e n t i t i e s and t h e i r a t t r i b u t e s . I t i s the documentation of d a t a s t o r e d i n the DBMS, a l o n g w i t h o t h e r d a t a e n t i t i e s ( t r a n s a c t i o n s , docu-ments) which a r e i n e x i s t e n c e i n an e n t e r p r i s e . The database management system s t o r e s d a t a e n t i t y i n f o r m a t i o n based on a s i n g l e , l i m i t e d view. I f one s t o r e s both d a t a and p r o c e s s i n f o r m a t i o n i n the d a t a d i r e c t o r y , r e l a t i o n s h i p s which a r e i m p l i e d i n the program - DBMS i n t e r f a c e and r e l a t i o n s h i p s which a r e not implemented through computer systems can be do-cumented and i n v e s t i g a t e d by u s e r s . The Data D i r e c t o r y F r o n t End To A DBMS I t has been suggested t h a t the d a t a d i r e c t o r y can be used t o r e p l a c e d a t a d e f i n i t i o n i n f o r m a t i o n s t o r e d i n a database management system. 8 S i n c e a l l d a t a elements and da t a s t r u c -t u r e s a r e s t o r e d i n the da t a d i c t i o n a r y , the DBMS s h o u l d be a b l e t o use t h a t i n f o r m a t i o n t o format i t s s t o r a g e a r e a f o r d a t a . T h i s i s the f u n c t i o n of the da t a d i c t i o n a r y i n the ANSI/SPARC d e f i n i t i o n . 9 Proponents of t h i s e x t e n s i o n t o the da t a d i c t i o n a r y c l a i m t h a t the i n f o r m a t i o n i s d u p l i c a t e d i n the DBMS and t h e r e f o r e , because the da t a d i c t i o n a r y i s more Robert B. C h a m b e r l a i n , "DBMS and Data D i c t i o n a r y : To Merge or Not?" Computerworld, 29 Oct. 1979, p.36, p.38. 9 ANSI/X3/SPARC, p.28. 2 4 g e n e r a l s o f t w a r e i d e a l l y s u i t e d f o r t h i s purpose, i t s h o u l d be the o n l y r e p o s i t o r y . T h i s format of the da t a d i r e c t o r y can be a c h i e v e d i n two ways: f r e e - s t a n d i n g and c o u p l e d . A f r e e - s t a n d i n g d a t a d i r e c -t o r y used t o f r o n t end the DBMS i s not p a r t of the DBMS pac-kage. I t can, t h e r e f o r e , s t o r e non-mechanized d a t a e n t i t i e s as w e l l as those whose v a l u e s can be r e t r i e v e d by the DBMS. Acce s s t o the d a t a d i r e c t o r y does not r e q u i r e t h a t d a t a be r e t r i e v a b l e from the DBMS. In a d d i t i o n , the da t a d i r e c t o r y can document a d i f f e r e n t s t o r e d d a t a format from t h a t which the DBMS s u p p o r t s . For example, i f the DBMS uses a network system t o format and s t o r e d a t a , the da t a d i c t i o n a r y can a l l o w r e l a t i o n s h i p s which a r e h i e r a r c h i c a l . An a d d i t i o n a l argument f o r the f r e e - s t a n d i n g d a t a d i r e c t o r y i s t h a t a c c e s s of d a t a i n the DBMS does not r e q u i r e p r i o r a c c e s s of the d a t a d i r e c t o r y , t h e r e i s no s o f t w a r e overhead f o r a DBMS a c c e s s . As such, DBMS r e t r i e v a l performance i s not a f f e c t e d . The a l t e r n a t e method of u t i l i z i n g a da t a d i r e c t o r y as a f r o n t end t o the DBMS i s t o c o u p l e them. T h i s would mean t h a t the d a t a d i r e c t o r y i s extended t o i n c l u d e d a t a s t o r a g e and r e t r i e v a l mechanisms, or the DBMS i s expanded t o i n c l u d e the f a c i l i t i e s f o r the s t o r a g e of d i c t i o n a r y and d i r e c t o r y a t t r i -25 b u t e s . 1 0 T h i s i m p l e m e n t a t i o n l o c a l i z e s the s t o r a g e of the metadata. I t may a l s o a l l o w f o r a more u n i f o r m method of s t o r i n g b oth the da t a d i r e c t o r y e n t i t i e s and the database e n t i t y v a l u e s . T h i s would reduce the number of u t i l i t i e s ne-c e s s a r y t o support both the DBMS and the d a t a d i r e c t o r y . In Sharman and Winterbottom, a d a t a d i c t i o n a r y and DBMS were up-dat e d a t the same tim e . For example, a da t a e n t i t y and i t s a t t r i b u t e s were added t o the d a t a d i c t i o n a r y , and s u b s e q u e n t l y v a l u e s f o r t h a t e n t i t y were added t o the DBMS. The p r i m a r y advantage t o u s e r s i n t h i s o r g a n i z a t i o n of da t a and metadata, they c l a i m , i s t h a t a c c e s s t o the DBMS can . be done w i t h an e n t i t y - t y p e s e a r c h i n the d a t a d i r e c t o r y , w i t h a l l i t s i n f o r -mation about the usage and r e l a t i o n s h i p s between p r o c e s s e s and d a t a , and then a s e a r c h f o r v a l u e s of t h a t e n t i t y i n the d a t a -base c o u l d be done. Other advantages of i n t e g r a t i n g t he fu n c -t i o n s of the da t a d i r e c t o r y w i t h t h o s e of the database manage-ment system i n c l u d e : 1. S e c u r i t y a g a i n s t u n a u t h o r i z e d a c c e s s i s c o n t r o l l e d a t one p o i n t . A l l i n f o r m a t i o n about u s e r s who have v a l i d c l e a r a n c e f o r data elements can be s t o r e d w i t h o u t d u p l i -c a t i o n . 1 0 G. C. H. Sharman and N. W i n t e r b o t t o m , "The Data D i c t i o n a r y F a c i l i t i e s of NDB," P r o c e e d i n g s of the F o u r t h I n t e r n a t i o n a l  C onference on Very Large Data Bases~TSept. 1978), pp. 186-197. 26 The d a t a d i r e c t o r y c an s t o r e a c c e s s p a t h l o g i c f o r r e p e -t i t i v e DBMS a c c e s s e s . T h i s c a n r e d u c e t h e amount o f t i m e n e c e s s a r y t o r e t r i e v e d a t a . The d a t a d i r e c t o r y c an s t o r e s t a t i s t i c s c o n c e r n i n g t h e a c c e s s of d a t a e n t i t i e s . T h i s c o u l d be u s e d by s y s t e m s a n a l y s t s i n d e f i n i n g new a p p l i c a t i o n s . D a t a v a l i d a t i o n c an be i n t e g r a t e d i n t o t h e d a t a b a s e management s y s t e m u s i n g p a r a m e t e r s s u p p l i e d by t h e d i r e -c t o r y . T h i s would i n c r e a s e t h e i n t e g r i t y o f d a t a s t o r e d i n t h e d a t a b a s e s y s t e m . A f a c t o r w h i c h s h o u l d be c o n s i -d e r e d b e f o r e d a t a v a l i d a t i o n i s i n c l u d e d as p a r t of t h e d a t a b a s e s y s t e m i s t h e d e c r e a s e i n i n f o r m a t i o n r e t r i e v a l p e r f o r m a n c e i f v a l i d a t i o n i s not n e c e s s a r y . V e r y comp-l e x s t o r e d r o u t i n e s may be needed t o e n s u r e t h a t a l l t h e v a r i o u s v a l i d a t i o n r u l e s c an be accommodated. A l t e r n a t i v e l y , s t o r e d r o u t i n e s c o u l d be so s i m p l e t h a t a d d i t i o n a l v a l i d a t i o n r o u t i n e s w r i t t e n i n t o d a t a e n t r y p rograms would r e s u l t i n r e d u n d a n c y o f d a t a v a l i d a t i o n . T h e s e c o n s i d e r a t i o n s a r e tempered by t h e c o n s i s t e n t app-l i c a t i o n of v a l i d a t i o n c r i t e r i a and e a s e of m o d i f i c a t i o n o f v a l i d a t i o n r u l e s s t o r e d . 27 2.3 D a t a R e s o u r c e D i c t i o n a r y The p r e c e d i n g d e s c r i p t i o n of t h e d a t a d i r e c t o r y ( w h i c h i n c l u d e s t h e d a t a d i c t i o n a r y ) has n o t e x p l i c i t l y named i t s u s e r s . T h i s i s due t o t h e e m p h a s i s on d e s c r i b i n g c l a s s i f i c a -t i o n s of m e t a d a t a s o f t w a r e . The u s e r s ' r e q u i r e m e n t s a r e d e s -c r i b e d more i n C h a p t e r 3, however, t h e major u s e r s o f t h e d a t a r e s o u r c e d i c t i o n a r y w i l l be d a t a p r o c e s s i n g s t a f f , t h e DBA, s y s t e m s a n a l y s t s , and programmers. The s t o r a g e o f m e t a d a t a a b o u t d a t a and p r o c e s s i n g e n t i -t i e s i s a tremendous new s o u r c e o f i n f o r m a t i o n a b o u t th e d a t a p r o c e s s i n g f u n c t i o n of t h e e n t e r p r i s e . In i d e n t i f y i n g t h e e n t i t i e s and a t t r i b u t e s of t h e d a t a r e s o u r c e d i c t i o n a r y (DRD), we can l o o k a t t h e f i v e main i n t e r f a c e s t o t h e d a t a r e s o u r c e d i c t i o n a r y . 1 1 E a c h of t h e s e i n t e r f a c e s d e s c r i b e s t h e manner i n w h i c h a u s e r ( w h i c h may be a p e r s o n or an a u t o m a t e d p r o -c e s s ) r e t r i e v e s i n f o r m a t i o n from t h e d i c t i o n a r y . 1. A p p l i c a t i o n d e v e l o p m e n t i n t e r f a c e . T h i s i n t e r f a c e would encompass t h e t e c h n i c a l d e s i g n and i m p l e m e n t a t i o n q u e s -t i o n s t h a t s y s t e m s a n a l y s t s , programmers, o r o p e r a t o r s may have o f d a t a e n t i t i e s o r p r o c e s s e s . The d a t a d i c -t i o n a r y must have d a t a t o s u p p o r t t h e s e t e c h n i c a l i n -q u i r i e s . The q u e s t i o n s p o s e d a r e o f t e n g e n e r a l b e c a u s e 1 T h e o d o r e W. Z i e h e , "What Management S h o u l d Know About IRM," C o m p u t e r w o r l d , 14 ( O c t . 13, 1980), In D e p t h 11. 28 o f t h e need f o r a wide s p e c t r u m of i n f o r m a t i o n c o m p l e t e -l y d e s c r i b i n g t h e d a t a , p r o c e s s , o r i n t e r f a c e e n t i t i e s e x a m i n e d . S i n c e s u c h q u e r i e s w i l l b e g i n w i t h v e r y b a s i c requests;,, and a r e t h e n honed by m o d i f i e r s , a c o m p l e t e i n t e r f a c e d i a l o g u e i s n e c e s s a r y . T h i s i n t e r f a c e would r e q u i r e t h e u s e r t o be a b l e t o s p e c i f y b o t h t h e t y p e o f i n f o r m a t i o n d e s i r e d and t h e f o r m a t i n w h i c h t h a t i n f o r -m a t i o n s h o u l d be p r e s e n t e d . U s e r i n t e r f a c e . T h i s i n t e r f a c e r e q u i r e s a d i a l o g u e w h i c h w i l l a l l o w t h e u s e r t o c o n c e p t u a l i z e d a t a and p r o -c e s s e s e a s i l y . In a d d i t i o n , i t i s n e c e s s a r y t o p r e s e n t d a t a i n s u c h a manner t h a t t h e u s e r can e a s i l y n a v i g a t e t h r o u g h t h e models ( r e p r e s e n t e d by r e l a t i o n s h i p s between e n t i t i e s ) w h i c h a r e s t o r e d i n t h e d a t a d i c t i o n a r y . The u s e r w i l l most l i k e l y i d e n t i f y s p e c i f i c d a t a or p r o c e s -s i n g e n t i t i e s i n h i s / h e r q u e r y and, t h e r e f o r e , must be p r e s e n t e d a s i m p l e , r e s t r i c t e d v i e w o f b o t h e n t i t i e s and r e l a t i o n s h i p s . As a r e s u l t o f t h e q u e r y t h e u s e r w i l l l i k e l y i n f l u e n c e t h e d a t a s t o r e d i n t h e d a t a d i c t i o n a r y by s p e c i f y i n g a d d i t i o n a l r e l a t i o n s h i p s o r e n t i t i e s . In t h i s i n t e r f a c e t h e r e l a t i o n s h i p s between d a t a and p r o -c e s s e s i s most i m p o r t a n t . The i n f o r m a t i o n p r o c e s s i n g i n t e r f a c e . T h i s i n t e r f a c e a l l o w s i n f o r m a t i o n p r o c e s s i n g s y s t e m s s u c h as d a t a b a s e s , d a t a management r o u t i n e s , and a p p l i c a t i o n programs t o 29 e x t r a c t a t t r i b u t e v a l u e s n e c e s s a r y f o r t h e i r p r o c e s s i n g . The method of query i s h i g h l y s t r u c t u r e d and f o r m a l i z e d . The v a l u e of a t t r i b u t e s i s the i n f o r m a t i o n e x t r a c t e d . 4. The d i s t r i b u t e d p r o c e s s i n t e r f a c e . T h i s i n t e r f a c e docu-ments l o c a t i o n a l e n t i t i e s a t a h i g h e r l e v e l of c o m p l e x i -t y than the d a t a d i r e c t o r y . In t h i s i n t e r f a c e the system w i l l e x t r a c t i n f o r m a t i o n about the d i s t r i b u t i o n and l o c a t i o n of i n f o r m a t i o n a c r o s s p h y s i c a l data s t o r a g e d e v i c e s , which may be l o c a l or remote. 5 . The c o n t r o l i n t e r f a c e . T h i s i n t e r f a c e i s used by the database a d m i n i s t r a t o r t o r e c o r d a t t r i b u t e s t h a t s u pport d o c u m e n t a t i o n , the v a l i d i t y .of d a t a s t o r e d i n the DBMS and the d a t a f i l e s , and s e c u r i t y t h a t s h o u l d be i m p l e -mented i n p r e v e n t i n g u n a u t h o r i z e d a c c e s s t o the d a t a . I n f o r m a t i o n r e t r i e v e d by the database a d m i n i s t r a t o r u s i n g t h i s i n t e r f a c e w i l l a l l o w him/her t o make d e c i -s i o n s c o n c e r n i n g the amount of i n f o r m a t i o n to be s t o r e d i n the d a t a r e s o u r c e d i c t i o n a r y . In meeting the i n f o r m a t i o n r e q u i r e m e n t s f o r the f i v e i n -t e r f a c e s d e s c r i b e d above, the DRD must not o n l y s t o r e metadata c o n c e r n i n g d a t a , p r o c e s s , and i n f o r m a t i o n i n t e r c h a n g e e n t i t i e s but a l s o : 1. L o c a t i o n a l i n f o r m a t i o n a t the machine a d d r e s s l e v e l . 30 2. S t a t i s t i c a l d a t a c o n c e r n i n g usage f r e q u e n c y , usage se-quence, such as a c c e s s p a t h , both a t the p h y s i c a l d a t a -base l e v e l and a t the c l e r k / f i l i n g c a b i n e t l e v e l . 3. Documentation of p h y s i c a l d e v i c e s such as computers, d i s c f i l e s , tape d r i v e s , and p e o p l e . 4. Resource c h a c t e r i s t i c s such as r e t r i e v a l t i m e , t r a n s f e r speed, and c a p a c i t y . 5. T e l e c o m m u n i c a t i o n s a t t r i b u t e s such as p r o t o c o l s , l i n e r a t e , and network c o n f i g u r a t i o n . Documentation of a l l DRD e n t i t e s must i n c l u d e compu-t e r i z e d and non-computerized e n t i t i e s and a l l o w f o r i n p u t from programs, o n - l i n e m o n i t o r s , database d i r e c t o r i e s , as w e l l as the c a p t u r e of data t h r o u g h the use of manually p r e p a r e d d a t a i n p u t . The u s e r s of the d a t a r e s o u r c e d i c t i o n a r y - data p r o c e s -s i n g s t a f f , f u n c t i o n a l d a t a a n a l y s t s i n v e s t i g a t i n g user r e -q u i r e m e n t s , and a u d i t o r s - can u t i l i z e the d a t a s t o r e d through a m u l t i t u d e of a p p l i c a t i o n subsystems. 1 2 These subsystems a r e used t o support the i n t e r f a c e s d e s c r i b e d e a r l i e r . 1 2 B r i t i s h Computer S o c i e t y , "Data D i c t i o n a r y Systems Working P a r t y R e p o r t , " Data Base, 9, No.4 (1977), 20-22. 31 S u b s y s t e m s w h i c h s u p p o r t d a t a p r o c e s s i n g s t a f f i n t h e d e s i g n , d e v e l o p m e n t , i m p l e m e n t a t i o n , and m a i n t e n a n c e o f s y s -tems i n c l u d e : 1. I m p a c t - o f - c h a n g e a n a l y s i s r o u t i n e s w h i c h a l l o w s t h e a n a -l y s t t o i d e n t i f y p r o g r a m s a f f e c t e d by a change i n d a t a s t r u c t u r e , or t h e d a t a f i l e s a f f e c t e d by a program modi-f i c a t i o n . The l o n g l e a d t i m e n e c e s s a r y t o d e v e l o p s y s -tems and the. a v e r a g e l e v e l of d o c u m e n t a t i o n compared t o t h e t u r n o v e r o f programmers and a n a l y s t s makes t h i s a h i g h p a y o f f u t i l i t y . 2. A p r o g r a m v e r s i o n c o n t r o l s y s t e m t o document c h a n g e s t o p r o g r a m s . T h i s would a l l o w p a c k a g e d s o f t w a r e t o be mo-d i f i e d y e t r e t a i n t h e a b i l i t y of a p p l y i n g s o f t w a r e up-g r a d e s , w i t h r e a s o n a b l e e f f o r t . 3. T e s t d a t a g e n e r a t i o n . T h i s u t i l i t y a l l o w s c o n s i s t e n t t e s t d a t a t o be g e n e r a t e d b a s e d on d a t a d e f i n i t i o n s s t o r e d . T h i s would a l l o w s y s t e m s d e v e l o p m e n t s t a f f t o t e s t more c o m p r e h e n s i v e l y and p r o v i d e a base t e s t f o r pr o g r a m m a i n t e n a n c e s t a f f . 4. Program code g e n e r a t o r . Many d a t a b a s e d e f i n i t i o n s , d a -t a b a s e c a l l s t a t e m e n t s , d a t a c o m m u n i c a t i o n s r o u t i n e s , j o b c o n t r o l s t a t e m e n t s , and v a l i d a t i o n r o u t i n e s a r e s t a n d a r d . W i t h t h e s y s t e m and hard w a r e i n f o r m a t i o n 32 s t o r e d i n t h e d a t a r e s o u r c e d i c t i o n a r y , s u c h code c o u l d be g e n e r a t e d a u t o m a t i c a l l y , o r p a r a m e t e r s f o r c o m p l e t i n g t h e d e v e l o p m e n t of t h e code c o u l d be p r e s e n t e d i n a u s e a b l e manner. O t h e r s u b s y s t e m s w h i c h would be u s e f u l , and c o u l d u t i l i z e i n f o r m a t i o n c o n t a i n e d i n t h e d a t a r e s o u r c e d i c t i o n a r y i n c l u d e : 1. A c c e s s c o n t r o l mechanisms. Because t h e d a t a r e s o u r c e d i c t i o n a r y has i n f o r m a t i o n c o n c e r n i n g d a t a a t t h e e l e -ment l e v e l , a c c e s s c o n t r o l c o u l d be i m p l e m e n t e d f o r b o t h p r o g r a m c o m p i l a t i o n and e x e c u t i o n . At c o m p i l e t i m e , b e c a u s e d a t a d e f i n i t i o n s and p rograms a r e b o t h d e f i n e d i n t h e DRD, u n a u t h o r i z e d programs c o u l d not be c o m p i l e d . E x e c u t i o n t i m e c o n t r o l would e n s u r e t h a t t h e p r o p e r p r o -gram and d a t a f o r m a t s were u s e d and would p e r m i t d a t a use s t a t i s t i c s t o be g a t h e r e d . T h i s s u b s y s t e m would use an i n t e r f a c e w h i c h would a l l o w f o r ad hoc o n - l i n e a c c e s s t o d a t a as w e l l as t h e t r a d i t i o n a l b a t c h p r o g r a m a c c e s s . I m p l e m e n t a t i o n c o u l d be a c c o m p l i s h e d by means of p r o gram c a l l s , s i m i l a r t o d a t a b a s e management s y s t e m a c c e s s . 2. D a t a r e s o u r c e d i c t i o n a r i e s , b e c a u s e t h e y c o n t a i n d e t a i l i n f o r m a t i o n c o n c e r n i n g p rograms and s o f t w a r e s y s t e m s , c o u l d f u n c t i o n as t h e i n t e r f a c e between u s e r r e q u e s t s , b o t h o n l i n e and b a t c h , ad hoc and p r e c o m p i l e d , and v a r i o u s d a t a b a s e management s y s t e m s (DBMS). B e c a u s e t h e 3 3 DBMS dat a d e f i n i t i o n s a r e s t o r e d i n the d a t a d i c t i o n a r y , programs c o u l d c a l l f o r d a t a t o the DRD which would, i n t u r n , c a l l each of the n e c e s s a r y DBMS systems t o comp-l e t e the r e t r i e v a l . In a d d i t i o n , the d a t a r e s o u r c e d i c -t i o n a r y c o u l d c o n t a i n s u f f i c i e n t i n f o r m a t i o n t o c o n t r o l the r e s t r u c t u r e and r e l o a d of DBMS d a t a . 3 . F i n a l l y , the dat a r e s o u r c e d i c t i o n a r y s h o u l d a l l o w f o r r e p o r t i n g of the s t o r e d i n f o r m a t i o n . R e p o r t i n g i s not l i m i t e d t o s i m p l e l i s t s or c a t a l o g u e s of a t t r i b u t e s , e n t i t i e s and r e l a t i o n s h i p s but s h o u l d i n c l u d e s t r u c t u r e diagrams f o r programs, f l o w c h a r t s f o r the systems a r -c h i t e c t u r e , a u d i t o r r e p o r t s which would p r e s e n t the r e -q u i r e d c a l l s t o e x t r a c t s e l e c t e d d a t a from f i l e s , d a t a usage s t a t i s t i c s , and p h y s i c a l r e s o u r c e a l l o c a t i o n and useage s t a t i s t i c s . Armed w i t h t h i s type of i n f o r m a t i o n , the dat a p r o c e s s i n g s t a f f c o u l d u l t i m a t e l y d e v e l o p r o u t i n e s t o s i m u l a t e system environments and o p t i m i z e the performance of both hardware and s o f t w a r e . The s t o r a g e and c o n t r o l of database metadata would reduce or remove the problems of c o n t r o l l i n g d a t a bases which r e l y on s p e c i f i c computer hardware, and would a l l o w f o r g r e a t e r f l e x i -b i l i t y i n u s i n g the c o r r e c t database s t r u c t u r e , based on the a p p l i c a t i o n r e q u i r e m e n t , w h i l e s t i l l making t h a t i n f o r m a t i o n a v a i l a b l e t o o t h e r a p p l i c a t i o n s r u n n i n g on o t h e r hardware. 34 2.4 Metadata D i e t i o n a r y The f i n a l l a y e r of metadata s o f t w a r e i s the metadata d i c -t i o n a r y . The p r e c e d i n g l a y e r s have m o d e l l e d the d a t a , p r o -c e s s e s , and the systems environment (hardware and s o f t w a r e ) , the f i n a l l a y e r models the e n t e r p r i s e i t s e l f . T h i s l a y e r con-t a i n s d e s c r i p t i o n s of d a t a t y p e s which a re a b s t r a c t . That i s , p r e v i o u s d e s c r i p t i o n s have been c o n c r e t e i n the e n t i t i e s des-c r i b e d ( f i l e s , programs, d a t a b a s e s ) . In the metadata d i c -t i o n a r y a l l d a t a an e n t e r p r i s e u s e s , and ways i n which t h a t d a t a i s used, i s d e s c r i b e d . Data which i s not p r e s e n t l y used, but may be used i n f u t u r e , or d a t a which was used i n the p a s t can a l s o be i n c o r p o r a t e d i n t o the realm of d a t a d e s c r i b e d . The i n f o r m a t i o n s t o r e d i n the metadata d i c t i o n a r y i s con-c e p t u a l . A c o n c e p t u a l view of d a t a may not be l i n k e d t o any i m p l e m e n t a t i o n of d a t a s t r u c t u r e s or p r o c e s s e s . T h i s concep-t u a l v i e w p o i n t p r o v i d e s a b a s i s f o r systems d e s i g n and o r g a n i -z a t i o n r e v i e w . In a d d i t i o n , i t p r o v i d e s a model f o r d e f i n i n g the scope of the d e s i g n , a l l o w i n g f o r b e t t e r c o n t r o l over imp-l e m e n t a t i o n of a p p l i c a t i o n systems. A d d i t i o n a l d a t a r e q u i r e d i n a d a t a r e s o u r c e d i c t i o n a r y , which s u p p o r t s the c o n c e p t u a l view i n c l u d e s the a b i l i t y t o r e c o r d e n t i t i e s such as employee, department or company. 1 3 These e n t i t i e s a r e d e s c r i b e d by a t t r i b u t e s such as the d a t a used, t a s k s performed, and ou t p u t 1 3 R i c h a r d G. Canning, ed., " I n s t a l l i n g a Data D i c t i o n a r y , " EDP  A n a l y z e r , 16, No. 1 (1978), 6. 35 g e n e r a t e d . R e l a t i o n s h i p s between e n t i t i e s a r e d e f i n e d i n terms of source documents, t a s k completed, approved or v e r i -f i e d , and o u t p u t f i l e d or d i s t r i b u t e d . In a d d i t i o n , e n t i t i e s a r e l i n k e d t o f u n c t i o n s , e v e n t s or o p e r a t i o n s which are p e r -formed. These o p e r a t i o n s can be at v a r i o u s l e v e l s of c o r -p o r a t e c o n t r o l (e.g. a d m i n i s t r a t i o n , s u p e r v i s i o n , or o p e r a t i o n s ) . At each l e v e l , the r e s p o n s i b i l i t y r e l a t e d t o a j o b c l a s s i f i c a t i o n i s i d e n t i f i e d . E v e nts a r e documented i n terms of o r i g i n , r e s p o n s i b i l i t y and e n t i t i e s a f f e c t e d . S e v e r a l v iews or v e r s i o n s of the c o n c e p t u a l model may be c o r -r e c t . For example, an e n t e r p r i s e d e s c r i p t i o n changes over t i m e . Where the c o n c e p t u a l d e s c r i p t i o n a t one p o i n t i n time may be c o r r e c t , changes i n the o r g a n i z a t i o n due t o r e o r g a n i z a -t i o n , changes i n b u s i n e s s o b j e c t i v e s , or the t a k e o v e r or merger w i t h a n o t h e r e n t e r p r i s e w i l l r e q u i r e d i f f e r e n t d e s c r i p -t i o n s a t those t i m e s , each one c o r r e c t a t t h a t i n s t a n t . Two o r g a n i z a t i o n s which have d i s c u s s e d and s u p p o r t e d con-c e p t u a l d a t a models w i t h i n the d a t a d i c t i o n a r y are the American N a t i o n a l Standards I n s t i t u t e (ANSI) and the B r i t i s h Computer S o c i e t y (BCS). 1" ANSI i d e n t i f i e d a c o n c e p t u a l schema l i n k e d t o an i m p l e m e n t a t i o n view of the d a t a b a s e , which d e s c r i b e d the database i n terms of a p p l i c a t i o n s , and the o p e r a t i o n a l view of the d a t a b a s e , which i d e n t i f i e d the p h y s i -1 4 ANSI/X3/SPARC, pp. 20-23; B r i t i s h Computer S o c i e t y , pp. 16-19. 6. 36 c a l s t o r a g e o f d a t a w i t h i n t h e s y s t e m . The ANSI c o n c e p t u a l schema d e s c r i b e d d a t a a t a meta l e v e l , however i t r e q u i r e d a s t r u c t u r e s i n c e i t was c o n t a i n e d w i t h i n a d a t a b a s e s y s t e m . The c o n c e p t u a l schema i n t h e ANSI model c o u l d o c c u r more t h a n o n c e . E a c h schema would be mapped t o i m p l e m e n t a t i o n and o p e r a t i o n a l v i e w s . BCS, on t h e o t h e r hand, d e f i n e d a c o n c e p t u a l model w h i c h d e s c r i b e d d a t a , e v e n t s , and r e l a t i o n s h i p s t o f u n c t i o n s . T h i s f o c u s d i d n o t d w e l l on mappings t o i m p l e m e n t a t i o n or o p e r a -t i o n a l v i e w s but s o u g h t o n l y t o d e s c r i b e c o r p o r a t e e n t i t i e s and f u n c t i o n s i n a manner w h i c h would a l l o w an a n a l y s i s o f d a t a a t t h e e n t e r p r i s e l e v e l . B e c a u s e i t was l e s s p r e c i s e , t h e BCS d e f i n i t i o n would be more d i f f i c u l t t o implement; howe-v e r i t gave a b r o a d e r s t a t e m e n t o f t h e p l a c e and f u n c t i o n of a c o n c e p t u a l v i e w . 3 7 CHAPTER 3 USERS OF THE DATA DICTIONARY The d a t a d i c t i o n a r y s y s t e m s u p p o r t s t h r e e main c l a s s e s of u s e r s : 1. T h o s e who use d a t a t o a c c o m p l i s h some g o a l o r o b j e c t i v e . F o r t h e s e i n d i v i d u a l s , d a t a i s an o b j e c t w h i c h i s mani-p u l a t e d t o a c h i e v e a d e s i r e d r e s u l t . They i n c l u d e t h e emp l o y e e s of an e n t e r p r i s e who a r e engaged i n i t s day t o day b u s i n e s s d e a l i n g s . 2 . T h o s e who a r e c h a r g e d w i t h p r o v i d i n g d a t a and i n f o r m a -t i o n t o u s e r s . These a r e i n d i v i d u a l s who p r o v i d e d a t a p r o c e s s i n g s e r v i c e s t o u s e r s making d a t a more e a s i l y r e t r i e v a b l e , s u m m a r i z i n g and c o l l e c t i n g d a t a and d e s i g -n i n g and i m p l e m e n t i n g s y s t e m s w h i c h r e d u c e t h e c l e r i c a l e f f o r t o f d a t a m a n i p u l a t i o n . They i n c l u d e s y s t e m s a n a -l y s t s , programmers, o p e r a t o r s , and d a t a e n t r y p e r s o n n e l . F o r them, t h e d a t a i s a s u b j e c t o f i n v e s t i g a t i o n i n i t s e l f and i s u s e d i n a g g r e g a t e or c o n c e p t u a l form o n l y . 3. T h o s e t h a t seek t o c o n t r o l d a t a s u c h as t h e D a t a Base A d m i n i s t r a t o r and D a t a P r o c e s s i n g Management. 38 F i g u r e 2 1 5 d e t a i l s the i n t e r a c t i o n of d i f f e r e n t f u n c -t i o n s w i t h the da t a d i c t i o n a r y . The m a t r i x a l s o i n c l u d e s two m e c h a n i c a l i n t e r f a c e s , w i t h c o m p i l e r s and da t a base management systems. We w i l l d e a l w i t h each of the s e groups i n t u r n and exa-mine, i n d e t a i l , t h e i r i n t e r a c t i o n w i t h the d a t a d i c t i o n a r y system. 3.1 The Data Base A d m i n i s t r a t o r The database a d m i n i s t r a t o r (DBA) i s the prime user of the d a t a d i c t i o n a r y . In managing an e n t e r p r i s e ' s d a t a , the database a d m i n i s t r a t o r must " b u i l d a d a t a d i c t i o n a r y t h a t c o r r e l a t e s and d e f i n e s the t h i n g s t h a t a r e i m p o r t a n t t o an e n t e r p r i s e , as w e l l as who uses them, where they a re used, when they a r e used, the s t a n d a r d s t h a t a p p l y , and the r e s p o n s i b i l i t y f o r a c c u r a c y and time l i m i t s " . 1 6 Major f u n c t i o n s of a database a d m i n i s t r a t o r a r e : 1 7 1. Data d e f i n i t i o n d o c u m e n t a t i o n . To p r o v i d e an a c c u r a t e 1 5 U h r o w c z i k , p. 338. 1 6 John K. Lyon, The Database A d m i n i s t r a t o r (New York: John W i l e y & Sons, 1976), p.5. 1 7 R i c h a r d D. S e c r e s t , "The Data A d m i n i s t r a t o r , " The  I n f o r m a t i o n Systems Handbook, ed., F. W. M c F a r l a n and R. L. Nowlan (Homewood, I l l i n o i s : Dow J o n e s - I r w i n , 1975) pp. 651-3. 3 9 DATA A D M I N I S T R A T I O N y y y y y y y DOCUMENTATION OF E N T I T I E S y y y y y DATA - P R O C E S S R E L A T I O N S H I P S y y y y y C O N C E P T U A L -I M P L E M E N T A T I O N M A P P I N G y y y y y I N C O N S I S T E N C Y C H E C K S y y / y y y y y y V E R S I O N CONTROL P L A N N I N G I N Q U I R Y y y y y / DATA D I V I S I O N S O U R C E G E N E R A T I O N y y y y D A T A B A S E SCHEMA G E N E R A T I O N y y y y y y V A L I D A T I O N MODULE SOURCE G E N E R A T I O N y y y A U D I T I N G QUERY G E N E R A T I O N y / y y y M U L T I P L E DBMS I N T E R F A C E y y y y DATA FLOW D E S I G N A I D Data F i g u r e 2 D i c t i o n a r y F u n c t i o n s 40 and complete d e f i n i t i o n of each e n t i t y used by an o r -g a n i z a t i o n . 2. The s e l e c t i o n and procurement of database management systems. 3. The a n a l y s i s of d a t a and p r o c e s s i n g r e q u i r e m e n t s and the d e s i g n of the database i n an o p t i m a l manner. 4. The p l a n n i n g , s u p e r v i s i o n , and r e v i e w of the i n i t i a l l o a d i n g of the DBMS w i t h o p e r a t i o n a l d a t a . 5. The development and enforcement of database s e c u r i t y and i n t e g r i t y s t a n d a r d s . 6. D e f i n i t i o n and documentation of p r o c e d u r e s and s t a n d a r d s f o r database maintenance. 7. E v a l u a t i o n and m o n i t o r i n g of database performance. 8. Enforcement of database s t a n d a r d s c o m p l i a n c e . 9. T r a i n i n g and l i a i s o n w i t h u s e r s . In p e r f o r m i n g t h e s e f u n c t i o n s the DBA r e q u i r e s a compre-h e n s i v e system. A p r o p e r l y d e v e l o p e d d a t a r e s o u r c e d i c t i o n a r y w i l l s u p p ort each of t h e s e f u n c t i o n s . 41 1. E n t i t y d o c u m e n t a t i o n . The d a t a d i c t i o n a r y c o n t a i n s d a t a e n t i t y d e f i n i t i o n s . The use of an a u t o m a t e d d a t a d i c -t i o n a r y by t h e DBA r e d u c e s t h e c l e r i c a l work n e c e s s a r y t o m a i n t a i n data, d e f i n i t i o n s . Once m e t a d a t a has been e n t e r e d i n t o an a u t o m a t e d s y s t e m , m a n i p u l a t i o n o f t h e m e t a d a t a t o answer q u e s t i o n s can be done by a p p l y i n g s y s t e m s r o u t i n e s r a t h e r t h a n r e s t r u c t u r i n g w r i t t e n d o c u -m e n t a t i o n . The d a t a b a s e a d m i n i s t r a t o r can d i s t r i b u t e t h e g a t h e r e d i n f o r m a t i o n and e n s u r e t h a t a l l u s e r s a g r e e . B e c a use d a t a i s d e f i n e d o n l y once t h e r e i s c e n -t r a l c o n t r o l of d e f i n i t i o n s . U s e r s c a n r e v i e w and s u g -g e s t c h a n g e s t o t h e c e n t r a l d e f i n i t i o n . I n a d d i t i o n , t h e f o r m a l i z a t i o n o f d e f i n i t i o n s e n s u r e s t h a t s t a n d a r d s c a n be m a i n t a i n e d . 2. S e l e c t i o n d a t a b a s e management s y s t e m s . A major t a s k i n t h e s e l e c t i o n of a d a t a b a s e management s y s t e m i s i n c h a r a c t e r i z i n g t h e d a t a t o be s t o r e d i n t h e DBMS. Volume, a c c e s s p a t h s , and s t r u c t u r e must a l l be c o n s i -d e r e d . The i d e n t i f i c a t i o n of t h e s e p a r a m e t e r s a s s i s t i n t h e s e l e c t i o n of a d a t a b a s e management s y s t e m , i d e n t i -f y i n g c a n d i d a t e s t h a t s a t i s f y p e r f o r m a n c e r e q u i r e m e n t s . The d a t a d i c t i o n a r y c o n t a i n s d a t a d e f i n i t i o n s and p e r -f ormance a t t r i b u t e s , w h i c h a s s i s t t h e DBA by f o r m a t t i n g t h e d a t a n e c e s s a r y t o make t h e s e l e c t i o n d e c i s i o n . 3. D a t a b a s e d e s i g n . In d e s i g n i n g t h e d a t a b a s e s t r u c t u r e 42 t h e DBA must e v a l u a t e t h e l e v e l o f r e d u n d a n c y i n d a t a t y p e s v e r s u s p e r f o r m a n c e c o n s i d e r a t i o n s . In d o i n g t h i s t h e DBA r e q u i r e s usage s t a t i s t i c s w h i c h show t h e r e l a -t i v e use o f d a t a . He/she c a n t h e n p e r f o r m an a n a l y s i s of t h e t y p i c a l a c c e s s s p e e d i n a r r i v i n g a t a r e a l i s t i c d a t a b a s e d e s i g n . By u s i n g i n f o r m a t i o n s t o r e d i n t h e d a t a r e s o u r c e d i c t i o n a r y t h e DBA s h o u l d be a b l e t o e v a -l u a t e a l t e r n a t i v e d e s i g n s i n a r r i v i n g a t h i s / h e r c o n c l u -s i o n . D a t a b a s e l o a d i n g . Once d e f i n i t i o n s have been a g r e e d t o by u s e r s , a d a t a b a s e management s y s t e m s has been s e -l e c t e d and i n s t a l l e d , and t h e d a t a b a s e has been d e -s i g n e d , i t i s n e c e s s a r y f o r d a t a t o ,be l o a d e d o r s t o r e d i n t h e d a t a b a s e . The d a t a d i c t i o n a r y a s s i s t s t h e d a t a -base a d m i n i s t r a t o r i n h i s / h e r t a s k by d e f i n i n g d a t a u s e , t h e o r i g i n o f t h e d a t a , u l t i m a t e r e s p o n s i b i l i t y f o r i t s c o r r e c t n e s s , and t h e p r o c e s s e s w h i c h w i l l a c c e s s t h e d a t a . T h e s e p r o c e s s e s c o u l d i n c l u d e ad hoc u s e r r e -q u e s t s , and b a t c h programs w h i c h e x t r a c t d a t a t o p r i n t on a r e p o r t , or u p d a t e t h e d a t a b a s e . T h i s c e n t r a l i n -f o r m a t i o n s o u r c e a l l o w s t h e d a t a b a s e a d m i n i s t r a t o r t o e n s u r e t h a t a c o m p l e t e d e f i n i t i o n of d a t a i s p r e s e n t b e f o r e h e /she a t t e m p t s t o l o a d t h e d a t a b a s e . D a t a b a s e s e c u r i t y and i n t e g r i t y s t a n d a r d s . The d a t a d i c t i o n a r y c o n t a i n s s e c u r i t y and i n t e g r i t y p a r a m e t e r s . 43 D e p e n d i n g on t h e c l a s s o f m e t a d a t a s o f t w a r e implemented and u t i l i t i e s w h i c h may be a v a i l a b l e , i t may be u s e d as a r e f e r e n c e by t h e DBA, or may a s s i s t i n t h e i m p l e m e n t a -t i o n o f e x e c u t i o n t i m e p r o c e d u r e s . E x e c u t i o n t i m e p r o -c e d u r e s , f o r example, would r e q u i r e d a t a u p d a t i n g t h e d a t a b a s e t o be p r o c e s s e d by a c e n t r a l i z e d v a l i d a t i o n p r o g r a m w h i c h would e x t r a c t s t a n d a r d v a l i d a t i o n parame-t e r s f r o m t h e d a t a d i c t i o n a r y . S i m i l a r l y , d a t a b a s e a c c e s s s e c u r i t y c o u l d be c o n t r o l l e d t h r o u g h s e c u r i t y p a r a m e t e r s w h i c h would be v e r i f i e d a t c o m p i l e o r e x e c u -t i o n t i m e . However, even a l e s s a u t o m a t e d s y s t e m w i t h o n l y p a r a m e t e r s f o r i n t e g r i t y o r s e c u r i t y s t o r e d i n t h e d a t a d i c t i o n a r y would enhance t h e d a t a b a s e a d m i n i s t r a t o r ' s c o n t r o l o f d a t a by e x p l i c i t l y d e f i n i n g t h e l e v e l of s t a n d a r d s e n f o r c e d . 6 . D a t a b a s e d e f i n i t i o n m a i n t e n a n c e . L i k e any o t h e r s o f t -ware, t h e d a t a b a s e d e f i n i t i o n i s not s t a t i c . I t i s t h e r e f o r e n e c e s s a r y t o document th e d e f i n i t i o n and t o be a b l e t o m o d i f y i t a c c o r d i n g t o t h e u s e r s ' n e e d s . The d a t a d i c t i o n a r y s u p p o r t s t h e DBA i n d o i n g t h i s by a l l o -wing t h e d o c u m e n t a t i o n o f more t h a n one v e r s i o n of d a t a -base d e f i n i t i o n . T h i s v e r s i o n c o n t r o l would a l l o w t h e DBA t o i d e n t i f y t h o s e d a t a d e f i n i t i o n s w h i c h a r e e f f e c -t i v e a s o p p o s e d t o t h o s e w h i c h a r e p r o p o s e d , o r s u p e r -s e d e d . D o c u m e n t a t i o n of v e r s i o n s i s an i m p o r t a n t t o o l i n c o n t r o l l i n g t h e e v o l u t i o n o f t h e d a t a b a s e s y s t e m , as 44 i t p r o v i d e s a b a s i s f o r d i s c u s s i o n and c o n t i n u i t y . 7. Database performance. In o p t i m i z i n g the performance of a database management system, the DBA r e q u i r e s s t a t i s -t i c s t h a t i d e n t i f y the u t i l i z a t i o n of the DBMS. The d a t a r e s o u r c e d i c t i o n a r y , a s s i s t e d by u t i l i t i e s , can c a p t u r e and s t o r e performance s t a t i s t i c s . Because the DRD i s not l i m i t e d t o c o n t r o l l i n g d a t a s t o r e d on a d a t a -base management system, performance s t a t i s t i c s f o r a l -t e r n a t e d a t a s t r u c t u r e s can be c a p t u r e d by the appro-p r i a t e u t i l i t i e s and s t o r e d . 8. E n f o r c i n g compliance of database s t a n d a r d s . The d a t a r e s o u r c e d i c t i o n a r y can a s s i s t the DBA i n e n f o r c i n g s t a n d a r d s by e n s u r i n g t h a t development m e t h o d o l o g i e s f o r d a t a use i n c l u d e the g e n e r a t i o n of database d e f i n i t i o n s and program d a t a d e f i n i t i o n s u s i n g r o u t i n e s which u t i -l i z e t he d e f i n i t i o n s s t o r e d i n the DRD. T h i s e f f o r t can be a s s i s t e d by the use of a u t i l i t y which compares the d a t a d e f i n i t i o n s t a t e m e n t s i n source programs w i t h the d e f i n i t i o n s s t o r e d i n the DRD. Any d i f f e r e n c e s a r e r e -p o r t e d i n an e x c e p t i o n r e p o r t . By u s i n g a h i g h l y v i -s i b l e , c e n t r a l i z e d documentation v e h i c l e , the DBA en-su r e s t h a t u s e r s w i l l be eager t o m a i n t a i n and use de-f i n i t i o n s s t o r e d i n the d a t a d i c t i o n a r y . 9. User t r a i n i n g and l i a i s o n . Because the d a t a r e s o u r c e 45 d i c t i o n a r y i s a c e n t r a l i z e d , h i g h l y f o r m a l i z e d d a t a de-f i n i t i o n t o o l , t he DBA has a p r o d u c t which can be the o b j e c t of user t r a i n i n g c o u r s e s . Once a t r a i n i n g p r o -gram has been e s t a b l i s h e d , the DRD f u n c t i o n s as an e a s i l y u n d e r s t o o d i n t e r f a c e between user views of d a t a and the da t a p r o c e s s i n g a p p l i c a t i o n of d a t a i n computer systems. Once d i f f i c u l t i e s i n o b t a i n i n g agreement over d a t a d e f i n i t i o n s have been r e s o l v e d , i t i s much e a s i e r f o r an a n a l y s t t o complete the database d e f i n i t i o n and p r o c e s s i n g r e q u i r e m e n t s d e s i g n . By m a i n t a i n i n g a d a t a d i c t i o n a r y , the DBA can a s s i s t the systems a n a l y s t by p r o v i d i n g a c c u r a t e copy l i b r a r i e s f o r i n c l u s i o n i n t o new programs. In a d d i t i o n , the DBA can ta k e c o n t r o l of d a t a d e f i n i t i o n s used i n t e s t i n g new programs, keeping them d i s t i n c t from p r o d u c t i o n d e f i n i t i o n s . T h i s r e l i e v e s the a n a l y s t of the r e s p o n s i b i l i t y over d a t a d e f i n i t i o n s f o r p r o d u c t i o n systems and en s u r e s t h a t maintenance of s y s -tems w i l l not a f f e c t p r o d u c t i o n d a t a v e r s i o n s , u n t i l a f t e r t e s t i n g i s complete. The database a d m i n i s t r a t o r uses the da t a r e s o u r c e d i c -t i o n a r y i n much the same way as a buyer uses an i n v e n t o r y con-t r o l system, t o p r o v i d e the i n f o r m a t i o n n e c e s s a r y t o make i n -t e l l i g e n t d e c i s i o n s which- o p t i m i z e performance and m i n i m i z e c o s t . 46 3.2 The Systems A n a l y s t The s y s t e m s a n a l y s t p e r f o r m s two main f u n c t i o n s . The f i r s t i s t h e d e v e l o p m e n t o f new s y s t e m s . An a n a l y s t i s r e s -p o n s i b l e f o r i d e n t i f y i n g f u n c t i o n a l and d a t a r e q u i r e m e n t s o f a u s e r and t r a n s l a t i n g t h a t f u n c t i o n a l and d a t a s p e c i f i c a t i o n i n t o an o p e r a t i o n a l s y s t e m . The s e c o n d f u n c t i o n i s m o d i f i c a t i o n or m a i n t e n a n c e o f an e x i s t i n g s y s t e m b a s e d on c h a n g i n g u s e r needs, due t o a new b u s i n e s s e n v i r o n m e n t , an i n c r e a s e i n t h e s y s t e m ' s s c o p e r e s u l -t i n g f r o m more s o p h i s t i c a t e d u s e r p r o c e s s i n g , o r c o r r e c t i o n of e r r o r s i n t h e o r i g i n a l s y s t e m c a u s e d by programming o r d e s i g n . In d e v e l o p i n g a new s y s t e m , t h e a n a l y s t can u t i l i z e t h e m e t a d a t a d i c t i o n a r y by d o c u m e n t i n g t h e c o n c e p t u a l view of t h e o r g a n i z a t i o n , i d e n t i f y i n g t h e s c o p e o f t h e s y s t e m and i t s i n -t e r f a c e s . 1 8 A c o n c e p t u a l v i e w o f t h e e n t e r p r i s e u t i l i z e s e n t i t i e s s u c h as i n d i v i d u a l s , p r o c e d u r e s , f i l e s , and r e p o r t s i n c o m p l e t i n g a h i g h l e v e l d e s c r i p t i o n of t h e e n t e r p r i s e . Once t h e a n a l y s t has i d e n t i f i e d t h e s c o p e of t h e new s y s t e m , a l o c a l c o n c e p t u a l model w h i c h i s s u b s e t t o t h e g l o b a l view of t h e e n t e r p r i s e , can be d e v e l o p e d . T h i s l o c a l c o n c e p t u a l model w i l l i d e n t i f y t h e e v e n t s w h i c h o c c u r i n t h e d e s i r e d s y s t e m , t h e e n t i t i e s ( i n d i v i d u a l s . , B r i t i s h Computer S o c i e t y , p. 10, p. 17. 47 d a t a , p r o c e d u r e s ) which are a f f e c t e d , and the p r o c e s s e s i n -v o l v e d . These p r o c e s s e s w i l l s p e c i f y r e l a t i o n s h i p s between e n t i t i e s . D e f i n i t i o n of the l o c a l c o n c e p t u a l model a l l o w s f o r a n a l y s t - u s e r d i a l o g u e i n broad g e n e r a l terms. The metadata d i c t i o n a r y s h o u l d be a b l e t o produce f u n c t i o n m a t r i c e s which map the p h y s i c a l o r g a n i z a t i o n of the e n t e r p r i s e t o f u n c t i o n s (see F i g u r e 3 ) , and i n f o r m a t i o n f l o w diagrams (see F i g u r e 4 ) , i d e n t i f y i n g the r e l a t i o n s h i p between d a t a , f u n c t i o n s , and o u t -p u t . 1 9 A f u n c t i o n a l d e s c r i p t i o n of the system w i l l a l l o w the system a n a l y s t t o e s t i m a t e the i m p l e m e n t a t i o n e f f o r t r e q u i r e d and t o p r e p a r e an e s t i m a t e of c o s t s and b e n e f i t s f o r the s y s -tem. Supported by a h i g h l e v e l of d o c u m e n t a t i o n , the system a n a l y s t can then review the j u s t i f i c a t i o n f o r i m p l e m e n t a t i o n of the system w i t h user p e r s o n n e l . U s i n g t h i s l o c a l c o n c e p t u a l model as a b a s i s , the a n a l y s t t r a n s l a t e s the c o n c e p t u a l d e s i g n i n t o a systems d e s i g n s u i -t a b l e f o r i m p l e m e n t a t i o n . In d o i n g t h i s the a n a l y s t i d e n t i -f i e s the d e t a i l e d d a t a items and d a t a s t r u c t u r e s n e c e s s a r y t o support the f u n c t i o n s . The a n a l y s t completes the d e s i g n by i d e n t i f y i n g user r e s p o n s i b i l i t i e s and work s t a t i o n s , d a t a vo-lumes and p r o c e s s i n g f r e q u e n c i e s , s e c u r i t y and p r i v a c y 1 9 K a t h l e e n S. Mendes, " S t r u c t u r e d Systems A n a l y s i s : A Technique t o D e f i n e B u s i n e s s Requirements," S l o a n Management  Review, 21, No. 4 (1980), 55,56. Function Matrix Warehousing Responsibility Function / / / ' / / / * / / / / p / Warehousing X Determine Inventory Requirements X Predict Demand Monitor Stock Levels Verify Inventory X X X Acquire Parts X Accept Shipment Examine Contents Store Parts Record Parts Arrival X X X X Dispatch Orders X Assemble Orders Pack Orders Ship Orders Record Shipment X X X X F i g u r e 3 F u n c t i o n M a t r i x Information Flow Diagram Dispatch Orders O <-! 3 0) rt O I—1 O < D DJ OJ 3 w • ID C •-t ft Stock Clerk Order Assembly File Assembly Desk Purchase Orders Stock & Nonstock Parts Key: — ^ —Information or material flows (^) —Business functions — Information stores ] ] — Sources or destinations of information or material out-side of the business operation — Sources or destinations of information outside of the network but inside the business operation Customers Packing Slips, Containers Shipping Dock Completed Order File Accounts Receivable Inventory Kardex 50 c o n s t r a i n t s on d a t a and p r o c e s s e s . The r e s u l t o f t h i s i m p l e -m e n t a t i o n d e s i g n i s t h e d e t a i l e d s y s t e m s d o c u m e n t a t i o n u s e d i n t h e programming and i n s t a l l a t i o n o f t h e s y s t e m . The m e t a d a t a d a t a b a s e can s t o r e b o t h t h e c o n c e p t u a l model and t h e i m p l e m e n t a t i o n d e s i g n . U s i n g c r o s s - r e f e r e n c e s and g r a p h i c a l o u t p u t s i m i l a r t o t h o s e shown, t h e a n a l y s t c a n e a s i l y p r o d u c e v e r s i o n s o f t h e d e s i g n w h i c h c a n be d i s c u s s e d w i t h t h e u s e r u n t i l t h e o p t i m a l d e s i g n i s c o m p l e t e . In m o d i f y i n g s y s t e m s , t h e a n a l y s t i s r e s p o n s i b l e f o r r e -v i e w i n g a s y s t e m w h i c h i s a l r e a d y i n p r o d u c t i o n . By r e v i e w i n g t h e d a t a r e s o u r c e d i c t i o n a r y o u t p u t , t h e a n a l y s t c a n i d e n t i f y t h e impact o f a change t o a d a t a s t r u c t u r e or a p r o g r a m on o t h e r p r o c e s s e s or d a t a . W i t h t h i s d o c u m e n t a t i o n , t h e a n a l y s t c a n i d e n t i f y t h e e f f o r t r e q u i r e d t o make m o d i f i c a t i o n s t o t h e e x i s t i n g s y s t e m , and can e n s u r e t h a t t h e change i s c o n s i s t e n t w i t h t h e e n t e r p r i s e c o n c e p t u a l v i e w . 3.3 The Programmer The programmer u s e s t h e d a t a d i r e c t o r y by e x t r a c t i n g de-f i n i t i o n s n e c e s s a r y t o p r e p a r e p r o g r a m s . 2 0 The programmer i s i n t e r e s t e d i n t h e d a t a e n t i t i e s s u c h as e l e m e n t s , r e c o r d s , f i l e s o r d a t a b a s e s t r u c t u r e s , and programming e n t i t i e s s u c h as 2 0 U h r o w c z i k , p. 332. 51 modules, programs and systems. Programmers a r e a l s o i n -t e r e s t e d i n the p h y s i c a l l o c a t i o n of data and o p e r a t i n g c h a r a -c t e r i s t i c s of programs. In u s i n g a da t a d i r e c t o r y , the p r o -grammer i n t e r f a c e s a t c o m p i l a t i o n or e x e c u t i o n t i m e . I f the da t a d i r e c t o r y system has a c o m p i l e r i n t e r f a c e , the programmer uses the d a t a d i r e c t o r y i n d e p e n d e n t l y of the program t o p r o -duce output which i s used d u r i n g c o m p i l a t i o n . Data d e f i n i -t i o n s , i n the form of copy l i b r a r i e s and program d e f i n i t i o n s , such as v a l i d a t i o n r o u t i n e s , a r e l i n k e d t o the source code a programmer has w r i t t e n . In a d d i t i o n , the programmer can use the d a t a d i r e c t o r y t o ge n e r a t e t a b l e s i n s t o r a g e which a p r o -gram can r e f e r e n c e . A d a t a d i r e c t o r y used a t e x e c u t i o n time i s s i m i l a r t o a database i n t h a t the program c a l l s the da t a d i r e c t o r y t o ex-t r a c t d a t a d e f i n i t i o n s ( f o r example, t o use v a l i d a t i o n c r i -t e r i a s t o r e d f o r d a t a e l e m e n t s ) , or t o c o n t r o l system p r o -c e s s e s ( f o r example the da t a d i r e c t o r y , because i t s t o r e s d a t a l o c a t i o n i n f o r m a t i o n , c o u l d c a l l a d d i t i o n a l DBMS systems i n r e t r i e v i n g d a t a ) . The use of the d a t a d i r e c t o r y as an i n t e r -mediary between the programs and m u l t i p l e DBMS systems i s a h i g h l y s o p h i s t i c a t e d e x e c u t i o n time i n t e r f a c e . The programmer can a l s o use the d a t a d i r e c t o r y t o gen e r a t e d a t a f o r t e s t i n g . By u t i l i z i n g the d a t a d e f i n i t i o n s s t o r e d i n the d a t a d i c t i o n a r y and a u t i l i t y which g e n e r a t e s c o n s i s t e n t t e s t d a t a based on thes e d e f i n i t i o n s , the program-mer i s r e l i e v e d of the burden of c r e a t i n g a t e s t model. The 52 d a t a r e s o u r c e d i c t i o n a r y can a l s o generate j o b c o n t r o l l a n -guage by u t i l i z i n g the systems d e f i n i t i o n s s t o r e d . The emphasis i n the programmer's use of the d a t a d i c -t i o n a r y i s i n a r e d u c t i o n i n the amount of s o u r c e code w r i t -t e n . S t a n d a r d program code such as e d i t modules, d a t a d e f i n i -t i o n s , database d e f i n i t i o n s and c a l l s , r e p o r t h e a d i n g s , f i l e d e f i n i t i o n s , and s p e c i a l c a l c u l a t i o n r o u t i n e s c o u l d be d i c -t i o n a r y g e n e r a t e d . 3.4 The O p e r a t i o n s Department The d a t a r e s o u r c e d i c t i o n a r y system can a s s i s t the o p e r a -t i o n s department i n c o n t r o l l i n g p r o d u c t i o n systems by p r o v i -d i n g s t a n d a r d i z e d documentation. Through u t i l i t i e s the DRD can a c t as a l i b r a r i a n f o r programs and d a t a , and a s s i s t the o p e r a t o r i n v e r s i o n c o n t r o l . Documentation of r e c o v e r y / r e s t a r t f o r programs can a l s o be m a i n t a i n e d . 2 1 Because the data r e s o u r c e d i c t i o n a r y r e c o r d s the mapping b e t -ween u s e r s and r e p o r t s , d i s t r i b u t i o n of r e p o r t s can be main-t a i n e d . By documenting the p h y s i c a l components of a system, the d a t a r e s o u r c e d i c t i o n a r y , a i d e d by u t i l i t i e s , can s t o r e machine p r o d u c t i v i t y d a t a . In p r o v i d i n g t h i s i n f o r m a t i o n , t h r e e a d d i t i o n a l t y p e s of B r i t i s h Computer S o c i e t y , p. 22; ANSI/X3/SPARC, p. 27. 53 metadata a r e n e c e s s a r y : 2 2 1. Systems c o n t r o l d a t a . T h i s i n c l u d e s i n f o r m a t i o n which w i l l a l l o w an o p e r a t o r t o make d e c i s i o n s c o n c e r n i n g se-c u r i t y , and a c c e s s . I n f o r m a t i o n s t o r e d s h o u l d i n c l u d e : a) a c c e s s r i g h t s t o d a t a ( d a t a b a s e s ) , d e v i c e s (word p r o c e s s o r s ) , and ou t p u t ( r e p o r t s ) b) d i s t r i b u t i o n of r e p o r t s t o u s e r s c) i d e n t i f i c a t i o n of a u t h o r i z a t i o n f o r the i n i t i a t i o n of j o b s . 2. Job management d a t a . In s u p p o r t i n g the e x e c u t i o n of t e s t and p r o d u c t i o n j o b s , the o p e r a t o r r e q u i r e s i n f o r m a -t i o n c o n c e r n i n g d e v i c e r e q u i r e m e n t s , parameters t o be i n p u t d u r i n g p r o c e s i n g t o c o n t r o l j o b c o n t r o l language, i n s t r u c t i o n s t o a l l o w r e c o v e r y from system f a i l u r e s and to r e s t a r t p r o c e s s i n g , i n s t r u c t i o n s which d e t a i l the a c t i o n n e c e s s a r y when e r r o r messages a r e r e t u r n e d from the system p r o c e s s , and f i l e and program v e r s i o n con-t r o l . 3. Resource management d a t a . The data r e s o u r c e d i c t i o n a r y can a s s i s t o p e r a t i o n s i n c o n t r o l l i n g and o p t i m i z i n g the 2 2 ANSI/X3/SPARC, p. 27,8. 54 use o f p h y s i c a l d e v i c e s by s t o r i n g i n f o r m a t i o n w h i c h i d e n t i f i e s s y s t e m d e v i c e s and t h e i r c o n f i g u r a t i o n , l e v e l s of u t i l i z a t i o n "and l o a d demands, t h e a s s i g n m e n t of a l t e r n a t e d e v i c e s when f a i l u r e o r u n a v a i l a b i l i t y o c -c u r s , and t h e a c c o u n t i n g and c h a r g e back o f d e v i c e u t i -l i z a t i o n t o t h e u s e r . Some of t h i s i n f o r m a t i o n i s h e l d i n v a r i o u s u t i l i t y s y s -tems u s e d by o p e r a t i o n s p e r s o n n e l . Much o f t h e i n f o r m a t i o n , however, i s n o t documented i n any p l a c e . The d a t a r e s o u r c e d i c t i o n a r y p r o v i d e s an o p p o r t u n i t y t o f o r m a l i z e t h e i n f o r m a -t i o n r e q u i r e m e n t s of o p e r a t i o n s and t o i n t e g r a t e t h i s d a t a w i t h t h e c o n c e p t u a l view o f o p e r a t i o n s . 3.5 The U s e r Group The r e m a i n i n g g r o u p t h a t can make use o f a d a t a d i c -t i o n a r y a r e i n d i v i d u a l s who a r e end u s e r s of d a t a and manage-ment, who must p l a n f o r t h e c o n t i n u i n g use and d e v e l o p m e n t o f t h e d a t a r e s o u r c e . The p r o l i f e r a t i o n of s p e c i a l i z e d d a t a p r o -c e s s i n g s y s t e m s , e a c h u s i n g t h e i r own d a t a b a s e , has had t h e e f f e c t of c r e a t i n g an e n t e r p r i s e w h i c h i s composed o f a number of e s s e n t i a l l y i n d e p e n d e n t f u n c t i o n a l e n t i t i e s . E m p l o y e e s a r e becoming f u n c t i o n a l l y s p e c i a l i z e d and may n o t be a b l e t o r e l a t e t h e i r t a s k s t o t h e o v e r a l l o p e r a t i o n of 55 t h e b u s i n e s s e n t e r p r i s e . 2 3 T h i s , i n t u r n , makes c o o r d i n a t i o n more d i f f i c u l t as fewer i n d i v i d u a l s know a l l f u n c t i o n s w h i c h a r e p e r f o r m e d and t h e d a t a w h i c h i s u s e d . I f an employee l e a v e s , no g u a r a n t e e can be made t h a t o t h e r e m p l o y e e s can meet t h e needs of t h e b u s i n e s s . T h i s p r o c e s s has been e x a c e r b a t e d by d a t a c a p t u r e s y s t e m s w h i c h a l l o w e n t r y o f t h e i n p u t a t t h e s o u r c e , r e d u c i n g t h e a c c e s s t o , and s h a r i n g o f , i n f o r m a t i o n . The m e t a d a t a d i c t i o n a r y r e s o l v e s some of t h e s e p r o b l e m s by a s s i s t i n g i n t h e t r a i n i n g o f new e m p l o y e e s . 2 " The metada-t a d i c t i o n a r y c an p r o v i d e a model o f b u s i n e s s f u n c t i o n s , b o t h g l o b a l l y and l o c a l l y , w h i c h can p r o v i d e p e r s p e c t i v e f o r t h e new employee. R e s p o n s i b i l i t y m a t r i c e s s t o r e d w i t h i n t h e d a t a d i c t i o n a r y c an i d e n t i f y w h i c h f u n c t i o n s a r e t o be p e r f o r m e d by e a c h employee, t h e o u t p u t o f t h o s e f u n c t i o n s , a n d . t h e d a t a t h a t i s n e c e s s a r y t o c o m p l e t e them. The m e t a d a t a d i c t i o n a r y c a n i d e n t i f y i n f o r m a t i o n t h a t i s s h a r e d between f u n c t i o n s and c a n document t h e s t o r a g e o f i n f o r m a t i o n . The d a t a d i c t i o n a r y a l l o w s f o r a c e n t r a l , a c c e s s i b l e s o u r c e of i n f o r m a t i o n about t h e o r g a n i z a t i o n s t o r e d a t a c o n c e p t u a l l e v e l . Changes i n p r o c e d u r e s i n one f u n c t i o n a l a r e a can be a n a l y z e d t o i d e n t i f y o t h e r a f f e c t e d a r e a s . As p l a n n e r s of i n f o r m a t i o n usage and t h e d e v e l o p m e n t of i n f o r m a t i o n s y s t e m s , management c a n use t h e same c o n c e p t u a l 2 3 B r i t i s h Computer S o c i e t y , p. 9. 2" Lawrence W. K r e i t z e r , "Data D i c t i o n a r i e s -- The Heart of IRM," I n f o s y s t e m s , 28, No.2 (1981), p.64,6. 56 m e t a d a t a d i c t i o n a r y t o i d e n t i f y where t h e d a t a model does not s e r v e t h e needs of t h e o r g a n i z a t i o n . T h i s a l l o w s f o r more e f f i c i e n t c o m m u n i c a t i o n o f i n f o r m a t i o n p l a n n i n g between mana-gement, d a t a p r o c e s s i n g , and u s e r s . In managing t h e d a t a r e s o u r c e , t h r e e t h i n g s a r e n e c e s -s a r y . 2 5 The f i r s t i s t o know where d a t a i s s t o r e d , and how i t i s u s e d . T h i s a l l o w s f o r t h e c o n t r o l l e d d i s s e m i n a t i o n of d a t a t o t h o s e i n d i v i d u a l s who r e q u i r e i t . In e s s e n c e t h i s f l o w o f d a t a i s t h e i n f o r m a t i o n s y s t e m of an o r g a n i z a t i o n . The s e c o n d r e q u i r e m e n t i s t h e a b i l i t y t o c o n t r o l t h e de-v e l o p m e n t of t h e i n f o r m a t i o n s y s t e m and t h e change i n usage of d a t a . T h i s c o n t r o l w i l l e n s u r e t h a t , a t a minimum, a s t a t u s quo of i n f o r m a t i o n usage c a n be m a i n t a i n e d , and t h e o r g a n i z a -t i o n can r e s p o n d t o i n f o r m a t i o n needs b a s e d on c h a n g e s i n i t s e x t e r n a l e n v i r o n m e n t . The t h i r d f a c t o r n e c e s s a r y f o r s u c c e s s f u l management o f d a t a i n an o r g a n i z a t i o n i s a p l a n f o r t h e change i n t h e i n f o r -m a t i o n s y s t e m t o o p t i m a l l y meet u s e r r e q u i r e m e n t s . T h i s p l a n s h o u l d f o c u s on t h e a p p l i c a t i o n o f d a t a p r o c e s s i n g r e s o u r c e s t o p r o v i d e d a t a t o u s e r s . T h e s e p l a n s w i l l be a b l e t o impose c o n t r o l s o v e r t h e c o l l e c t i o n , o r d e r i n g , s t o r a g e and use of d a t a and c e n t r a l i z e t h e a u t h o r i t y o v e r d a t a . 2 5 B r i t i s h Computer S o c i e t y , p. 8. 57 CHAPTER 4 SURVEY OF COMMERCIAL DATA DICTIONARIES  I n t r o d u c t i o n T h i s c h a p t e r w i l l examine f i v e d a t a d i c t i o n a r y p a c k a g e s c u r r e n t l y a v a i l a b l e c o m m e r c i a l l y . T h e s e p a c k a g e s r e p r e s e n t t h e major s y s t e m s i n u s e . D a t a f o r t h e r e v i e w was o b t a i n e d f r o m f o u r p u b l i c a t i o n s w h i c h e v a l u a t e d c o m m e r c i a l p r o d u c t s . M a n u f a c t u r e r s l i t e r a t u r e was a l s o o b t a i n e d f o r a l l p a c k a g e s r e v i e w e d . T a b l e 1 summarizes t h e s o u r c e of i n f o r m a t i o n f o r e a c h of t h e s y s t e m s r e v i e w e d . The f o u r p u b l i c a t i o n s were: 1. D a t a D i c t i o n a r y Systems by Henry C. L e f k o v i t s . T h i s book was p u b l i s h e d i n 1977, and i s t h e most comprehen-s i v e d i s c u s s i o n o f d a t a d i c t i o n a r y s y s t e m s t o d a t e . I t b r i e f l y d e s c r i b e s t h e d e f i n i t i o n , use and f e a t u r e s o f d a t a d i c t i o n a r y s y s t e m s , and t h e n e v a l u a t e s s i x major s y s t e m s . In t h e e v a l u a t i o n , t h e a u t h o r spends a p p r o x i -m a t e l y one h a l f of t h e t e x t d e s c r i b i n g t h e d a t a d e s c r i p -t i o n l a n g u a g e f o r t h e e n t i t i e s and a t t r i b u t e s . 2. T e c h n i c a l P r o f i l e of Seven D a t a E l e m e n t D i c t i o n a r y / D i r e c t o r y S y s t e m s , by B e l k i s Leong-Hong and B e a t r i c e M a r r o n . T h i s s t u d y was p u b l i s h e d i n 1977. w w M K z o M EH P O W M 00 P 00 ««; o EH 00 P P \ \ \ \ \ \ \ \ » CULLINANE - IDD CC w o «*; z «»; EH s 1 PM W SYNERGETICS -DATA CATALOGUE 2 UNIVERSITY COMPUTING -UCC-10 IBM-DB/DC DAW DICTIONARY ICI - DDS CINCOM - DCS T a b l e I I n f o r m a t i o n S o u r c e s — D a t a D i c t i o n a r y P a c k a g e s 59 T h r e e q u a r t e r s o f t h e p u b l i c a t i o n d e s c r i b e d d a t a d i c -t i o n a r i e s , d e f i n e d t h e s u r v e y m e t h o d o l o g y , and d e s c r i b e d t h e f e a t u r e l i s t u s e d t o e v a l u a t e t h e s e v e n s y s t e m s . The p r o f i l e c o n s i s t s of 52 f e a t u r e s p r e s e n t e d i n t a b u l a r f o r m . D a t a D i c t i o n a r y Systems by J.D. Lomax. T h i s book was p u b l i s h e d i n 1977, and r e v i e w e d e i g h t s y s t e m s a v a i l a b l e i n t h e U n i t e d Kingdom. A p p r o x i m a t e l y 40% of t h e book d e a l s w i t h t h e d e f i n i t i o n , u s e s and i m p l e m e n t a t i o n of a d a t a d i c t i o n a r y s y s t e m . A s e t of 24 q u e s t i o n s i s u s e d t o e v a l u a t e t h e p a c k a g e s . No e x a m i n a t i o n o f i n p u t d a t a l a n g u a g e i s done, u n l i k e i n L e f k o v i t s , where t h e d i s c u s -s i o n was e x t e n s i v e . A S u r v e y of D a t a D i c t i o n a r i e s by R o b e r t M. C u r t i c e and E. M a r t i n Diekmann. T h i s a r t i c l e , p u b l i s h e d i n M a r ch 1981, p r e s e n t e d a b r i e f l o o k a t n i n e p o p u l a r d a t a d i c -t i o n a r y s y s t e m s w h i c h would r u n on IBM 360/370, 43XX, and 30XX c o m p u t e r s . The a u t h o r s a l l o c a t e d one page t o e a c h s y s t e m , f o c u s i n g on d a t a f l o w w i t h i n t h e s y s t e m , e n t i t i e s , i n p u t s , and i n t e r f a c e s . 60 The a u t h o r ' s a n a l y s i s o f e a c h package w i l l f o c u s on f o u r c h a r a c t e r i s t i c s : 1. The e n t i t y t y p e s s u p p o r t e d by e a c h s y s t e m . 2. The methods a v a i l a b l e t o i n p u t d a t a i n t o t h e d i c t i o n a r y s y s t e m . 3. The o u t p u t p r o d u c e d by t h e s y s t e m ( e . g . r e p o r t s , c o p y l i b r a r i e s , d a t a b a s e d e f i n i t i o n s ) . 4. S e c u r i t y f e a t u r e s a v a i l a b l e i n each s y s t e m . 4.1 Datamanager Datamanager i s m a r k e t e d by MSP, I n c . o f London, E n g l a n d , and i s r e p o r t e d t o have 500 i n s t a l l a t i o n s . I t i s w r i t t e n i n IBM A s s e m b l e r f o r t h e IBM 360/370 e n v i r o n m e n t . I t w i l l a l s o o p e r a t e on any c o m p a t i b l e m a i n f r a m e s . Datamanager w i l l s u p -p o r t IMS, DL/1, and o t h e r DBMS s y s t e m s w h i c h a r e s u p p o r t e d on t h e IBM h a r d w a r e . Datamanager s u p p o r t s s e v e n main e n t i t i e s as w e l l a s u s e r d e f i n e d s y n t a x . The main e n t i t i e s a r e : 1. ITEM. The l o w e s t l e v e l o f d a t a w i t h a t t r i b u t e s s u c h a s l a n g u a g e a l i a s , d e s c r i p t i o n , i n p u t and o u t p u t f o r m a t s , 61 name, l e n g t h , p i c t u r e , and v a l u e r a n g e . GROUP. A g r o u p i s a c o l l e c t i o n of i t e m s or g r o u p s , w i t h u n l i m i t e d n e s t i n g . F I L E , w h i c h i s a c o l l e c t i o n of ITEMS and GROUPS. A t t r i b u t e s i n c l u d e CONTENT, ALIGNMENT, and FORMAT, w h i c h d e s c r i b e t h e ITEMS and GROUPS, as w e l l a s ORGANIZATION ( i n d e x e d , s e q u e n t i a l ) , SORT p a r a m e t e r s , DEVICE and S I Z E . DATABASE, wh i c h d e f i n e s t h e d a t a b a s e u s i n g a t t r i b u t e s w h i c h a r e p a r t i c u l a r t o t h a t d a t a b a s e . F o r example, IMS-DATABASE w i l l have a t t r i b u t e s s u c h as SEGMENT, SEARCH-KEY, PHYSICAL-PARENT, LOGICAL-PARENT and LOGICAL-CHILD. S p e c i a l a t t r i b u e s a r e p r o v i d e d f o r e a c h of t h e d a t a b a s e s s u p p o r t e d by Datamanager. MODULE. T h i s i s a c o l l e c t i o n o f program l a n g u a g e s t a t e -ments p e r f o r m i n g an a c t i o n . The a t t r i b u t e s of MODULE a r e CALLS, INPUTS, OUTPUTS, and UPDATES. PROGRAM, w h i c h i s a g r o u p o f modules. PROGRAMS have t h e same a t t r i b u t e s a s MODULES, e x c e p t t h a t t h e y CONTAIN MODULES r a t h e r t h a n C A L L i n g them. SYSTEM. The SYSTEM, w h i c h i s t h e h i g h e s t l e v e l i n t h e p r o c e s s i n g h i e r a r c h y , i s composed of PROGRAMS, o r o t h e r 62 SYSTEMS t o an u n l i m i t e d l e v e l of n e s t i n g . Systems and s u b s y s t e m s a r e b o t h r e p r e s e n t e d by t h e SYSTEM e n t i t y . Datamanager a l s o a l l o w s f o r t h e d e f i n i t i o n o f u s e r e n t i -t i e s . T h i s i s done by u s i n g t h e b a s i c Datamanager e n t i t i e s and CATALOG a t t r i b u t e s t o e s t a b l i s h r e l a t i o n s h i p s . F o r example, DATAFLOW e n t i t i e s a r e d e f i n e d a s GROUPS c o n t a i n i n g ITEMS. PROCESS e n t i t i e s a r e a s p e c i a l c a s e of Datamanager SYSTEM e n t i t i e s and have DATAFLOW as INPUT and OUTPUT a t t r i -b u t e s . C o n c e p t u a l d e s i g n s c an be documented u s i n g r e g u l a r Datamanager e n t i t i e s . U s i n g s e a r c h commands, and t h e CATALOG a t t r i b u t e s , q u e s t i o n s s u c h a s : WHAT FORMS 'DATAFLOW' 'ACCOUNTING' c o u l d i d e n t i f y t h e d a t a f l o w s u s e d by t h e a c c o u n t i n g d e p a r t -ment. GROUP e n t i t i e s i n t h e a c c o u n t i n g d e p a r t m e n t would be c o d e d : CATALOG 'DATAFLOW' 'ACCOUNTING' I n p u t t o Datamanager c a n be done o n l i n e or i n b a t c h mode. U t i l i t i e s a r e p r o v i d e d f o r e x t r a c t i n g d a t a d e f i n i t i o n s from COBOL and PL/1 d a t a d i v i s i o n s , and from IMS, IDMS, TOTAL, ADABAS, and S/2000 d a t a b a s e management s y s t e m s . T h e s e d e f i n i -t i o n s c a n be s t o r e d and m o d i f i e d by t h e DBA b e f o r e l o a d i n g them i n t o t h e d a t a d i c t i o n a r y . The CONVERT command a l l o w s t h e DBA t o i d e n t i f y i n c o n s i s t e n c i e s w h i c h must be r e s o l v e d b e f o r e d a t a i s e n t e r e d i n t o t h e d i c t i o n a r y . 63 Datamanager p r o d u c e s r e p o r t s f o r e a c h of t h e e n t i t i e s s t o r e d i n t h e sys t e m , l i s t i n g a l l a t t r i b u t e s . Datamanager a l s o p r o d u c e s c r o s s r e f e r e n c e r e p o r t s . T h i s i s done u s i n g t h e REPORT command, which t r a c e s a l l r e f e r e n c e s l o w e r t h a n t h e s p e c i f i e d o c c u r r e n c e . F o r example, EMPLOYEE-FILE, a F I L E o c -c u r r e n c e w i l l l i s t a l l r e f e r e n c e s t o GROUPS and ITEMS. Commands i d e n t i f y i n g usage ( s u c h a s ITEMS i n F I L E S , or ITEMS i n PROGRAMS) a r e a v a i l a b l e i n b a t c h and o n l i n e mode. Th e s e commands have s e l e c t i v i t y p a r a m e t e r s w h i c h a l l o w t h e u s e r t o c o n t r o l t h e amount o f i n f o r m a t i o n d i s p l a y e d . Datamanager, t h r o u g h t h e PRODUCE command, p r e p a r e s d a t a d i v i s i o n s f o r COBOL and PL/1, BAL and MARK IV progr a m s , as w e l l as D a t a D e f i n i t i o n Language s t a t e m e n t s f o r ADABAS, IDMS, IMS, DL/1-D0S-VS, MARK IV, S/2000, and TOTAL. Datamanager a l l o w s f o r t h r e e l e v e l s o f s e c u r i t y : 1. CONTROLLER. The CONTROLLER g e n e r a t e s t h e d i c t i o n a r y and a s s i g n s p a s s w o r d s and p r i o r i t y l e v e l s t o u s e r s . 2. USERS. USERS a r e g i v e n a c c e s s t o t h e d i c t i o n a r y by t h e CONTROLLER and a r e a s s i g n e d a p r i o r i t y l e v e l . The p r i o r i t y l e v e l p e r m i t s t h e u s e r t o p e r f o r m commands p r o -v i d e d t h a t t h e i r l e v e l i s e q u a l t o o r h i g h e r t h a n t h e s e c u r i t y l e v e l r e q u i r e d . 64 3. OWNERS. OWNERS a r e g i v e n o w n e r s h i p of d i c t i o n a r y e n t i t y o c c u r r e n c e s and may, i n t u r n , d e f i n e p r i o r i t y l e v e l s f o r a c c e s s t o t h e i r d a t a t o o t h e r USERS. T h i s a l l o w s d a t a t o be p r o t e c t e d from i n d i v i d u a l u s e r s and, f u r t h e r , from g r o u p s o f commands i s s u e d by USERS. An e n t i t y c a n have t h r e e s e c u r i t y l e v e l s : 1. A c c e s s s e c u r i t y , w h i c h c o n t r o l s commands u s e d t o o u t p u t i n f o r m a t i o n from t h e d i c t i o n a r y . 2. A l t e r s e c u r i t y , w h i c h c o n t r o l s a d d i t i o n and m o d i f i c a t i o n o f o c c u r r e n c e s i n t h e d i c t i o n a r y . 3. Remove s e c u r i t y , w h i c h c o n t r o l s t h e d e l e t i o n of d a t a f r o m t h e d i c t i o n a r y . 4.2 DB/DC D a t a D i c t i o n a r y The DB/DC D a t a D i c t i o n a r y i s IBM's d i c t i o n a r y s y s t e m i n -t e n d e d p r i m a r i l y f o r t h e s u p p o r t o f IMS and DL/1 d a t a b a s e s . I t u t i l i z e s 6 DL/1 d a t a b a s e s and w i l l s u p p o r t o n l y IMS and DL/1, on IBM o r p l u g - c o m p a t i b l e m a i n f r a m e s . I t r e q u i r e s a b a t c h r e g i o n of 560K of v i r t u a l s t o r a g e t o r u n . DB/DC D a t a D i c t i o n a r y s u p p o r t s 15 p r e - d e f i n e d s u b j e c t c a t e g o r i e s ( e n t i t i e s ) . I t a l s o a l l o w s f o r up t o 200 u s e r - d e -65 f i n e d c a t e g o r i e s ( e n t i t i e s ) . The IBM s u p p l i e d e n t i t i e s can be b r o k e n down i n t o t h r e e g r o u p s . 1. D a t a e n t i t i e s : a) ELEMENT b) SEGMENT c) PCB d) DATABASE 2 . P r o c e s s e n t i t i e s : a) SYSTEM b) JOB c) PROGRAM d) MODULE 3. D a t a I n t e r f a c e e n t i t i e s : a) TRANSACTION b) PSB c ) SYSDEF d) DDUSER ELEMENT can be u s e d t o i d e n t i f y an i n d i v i s i b l e u n i t of d a t a or a g r o u p , t h r o u g h t h e CONTAINS a t t r i b u t e . A t t r i b u t e s a r e i n c l u d e d f o r COBOL o r PL/1 s p e c i f i c d e f i n i t i o n s . SEGMENT ca n be u s e d f o r b o t h IMS segment and c o n v e n t i o n a l r e c o r d u s e . The PCB e n t i t y i s u s e d t o d e s c r i b e t h e c o l l e c t i o n of ELEMENTS t o w h i c h a p r o g r a m has a c c e s s . A t t r i b u t e s of t h e PCB i d e n t i f y 66 whether i t i s a s s o c i a t e d w i t h a d a t a b a s e , a c o n v e n t i o n a l f i l e o r a t e l e p r o c e s s i n g t r a n s a c t i o n . The DATABASE e n t i t y can be u s e d t o d e s c r i b e b o t h DL/1 d a t a b a s e s and n o n - D L / l f i l e s ( d a t a s e t s ) . P r o c e s s i n g e n t i t i e s a r e a l l d e s c r i b e d by a t t r i b u t e s s u c h a s Name, D e s c r i p t i o n and U s e r . S i m p l e r e l a t i o n s h i p s between P r o c e s s e n t i t i e s and d a t a e n t i t i e s c a n be s e t up u s i n g t h e ADD-RELATIONSHIP command. PROGRAM e n t i t i e s have a d d i t i o n a l a t t r i b u t e s s u c h as p r o g r a m l a n g u a g e (PGMLNG) and program t y p e (PGMTYPE), whose a l l o w a b l e v a l u e s a r e T ( t e l e p r o c e s s i n g ) , D ( d a t a b a s e ) , and BATCH. D a t a i n t e r f a c e e n t i t i e s a l l o w f o r t h e s p e c i f i c a t i o n o f e n t i t i e s d e s c r i b i n g t h e r e l a t i o n s h i p between t h e d a t a d i c -t i o n a r y and u s e r (DDUSER), t h e s y s t e m and t h e d a t a b a s e (SYSDEF), programs and t h e d a t a b a s e ( P S B ) , and t h e p r o g ram and o n - l i n e t r a n s a c t i o n s (TRANSACTION). DDUSER c o n t a i n s s e c u r i t y i n f o r m a t i o n and p a s s w o r d s f o r a l l u s e r s . SYSDEF i s u s e d t o document t h e IMS/VS s y s t e m d e f i n i t i o n i n f o r m a t i o n ; PSB i s u s e d t o document the d a t a b a s e segments w h i c h a r e a v a i l a b l e t o a p a r t i c u l a r p rogram i n an IMS e n v i r o n m e n t . U s e r d e f i n e d e n t i t i e s a r e d e f i n e d by u s i n g t h r e e a d d i -t i o n a l " m e t a - e n t i t i e s " . CATEGORY i d e n t i f i e s t h e u s e r - d e f i n e d e n t i t y . F o r example, t h e u s e r may want t o s t o r e a t t r i b u t e s o f DOCUMENTS, PROGRAMMERS or DEPARTMENTS. In d e f i n i n g t h e CATEGORY, A L I A S e s can be r e c o r d e d , a DESCRIPTION can be m a i n -6 7 t a i n e d , and s y n t a x r u l e s c a n be d e f i n e d . ATTRTYPE a l l o w s t h e u s e r t o d e f i n e a t t r i b u t e s f o r t h e c a t e g o r y . RELTYPE a l l o w s f o r named r e l a t i o n s h i p s t o be e s t a b l i s h e d between u s e r - d e f i n e d e n t i t i e s and s y s t e m , o r o t h e r u s e r - d e f i n e d e n t i t i e s . I n p u t t o t h e DB/DC D a t a D i c t i o n a r y i s t h r o u g h o n l i n e d i s -p l a y f o r m s , w h i c h i n c l u d e e x p l a n a t i o n f r a m e s , o r t h r o u g h a b a t c h i n p u t s t r e a m , f o r b u l k d a t a e n t r y . D a t a d e f i n i t i o n s c a n be c a p t u r e d from COBOL s o u r c e s t a t e m e n t s or PL/1 s t r u c t u r e d e c l a r a t i o n s . D a t a d e f i n i t i o n s c a n a l s o be c r e a t e d from d a t a -base d e s c r i p t i o n (DBD) and p r o g r a m s p e c i f i c a t i o n b l o c k (PSB) l i b r a r i e s . O u t p u t from t h e d a t a d i c t i o n a r y i n c l u d e s b o t h r e p o r t s and g e n e r a t e d s o u r c e s t a t e m e n t s . DB/DC D a t a D i c t i o n a r y p r o d u c e s r e p o r t s t h r o u g h two commands: 1. REPORT. T h i s command i s u s e d t o do e n t i t y r e p o r t i n g . A l l o r some a t t r i b u t e s o f a g i v e n e n t i t y o c c u r r e n c e , t h e names and d e f i n i t i o n s of e n t i t y t y p e s , o r r e p o r t s of g e n e r a t e d programming c o d e c a n a l s o be p r i n t e d u s i n g t h i s command. 2. SCAN. T h i s command a l l o w s t h e u s e r t o s e a r c h f o r a s p e -c i f i e d c h a r a c t e r s t r i n g i n t h e NAME, or e n t i t y d e s c r i p -t i o n f i e l d of an e n t i t y t y p e or a s p e c i f i e d r e l a t e d e n t i t y t y p e . 68 G e n e r a t e d s o u r c e s t a t e m e n t s can be c r e a t e d f o r d a t a b a s e d e f i n i t i o n s (DBD-OUT), p r o g r a m s t a t u s b l o c k s (PSB-OUT) and f o r d a t a s t r u c t u r e s i n COBOL, PL/1 o r A s s e m b l e r l a n g u a g e (STRUCTURE-OUT). U s e r s can implement o t h e r u t i l i t i e s w h i c h i n t e r a c t w i t h t h e d a t a d i c t i o n a r y d a t a b a s e u s i n g t h e EXECUTE command. The s e programs can be u s e d t o p r o d u c e c u s t o m r e p o r t s o r p r o v i d e c u s t o m i z e d e r r o r messages t o o n - l i n e u s e r s . The i n t e r f a c e i s t h r o u g h t h e D i c t i o n a r y and do e s not a c c e s s d i c -t i o n a r y d a t a b a s e s d i r e c t l y . No u p d a t e o f t h e d i c t i o n a r y d a t a i s p o s s i b l e e x c e p t t h r o u g h t h e d a t a d i c t i o n a r y v a l i d a t i o n r o u -t i n e s . S e c u r i t y i s p r o v i d e d t h r o u g h t h e use o f t h e DDUSER sub-j e c t c a t e g o r y . A t t r i b u t e s s u c h as U s e r ID, p a s s w o r d and s t a t u s c o d e s c a n be s p e c i f i e d . S i g n o n c a n be c o n t r o l l e d a t t h e DB/DC D a t a D i c t i o n a r y menu l e v e l o r t h e IMS/VS or CICS d a t a c o m m u n i c a t i o n i n t e r f a c e l e v e l . The s e c u r i t y f e a t u r e s a l l o w f o r r e a d , o r r e a d and u p d a t e a c c e s s t o a p r e - s p e c i f i e d number o f s u b j e c t c a t e g o r i e s ( e n t i t i e s ) . 4.3 D a t a C a t a l o g u e 2 D a t a C a t a l o g u e 2 i s a d i c t i o n a r y p a c k a g e m a r k e t e d by S y n e r g e t i c s C o r p . of B e d f o r d , M a s s a c h u s e t t s . I t i s w r i t t e n i n ANSI COBOL and can be imp l e m e n t e d on IBM, UNIVAC and CDC m a c h i n e s and t h e i r p l u g c o m p a t i b l e c o u n t e r p a r t s . I t f e a t u r e s a l a r g e number o f DBMS i n t e r f a c e s and i s d e s i g n e d f o r l a r g e 6 9 o r g a n i z a t i o n s . Over 150 i n s t a l l a t i o n s a r e r e p o r t e d , one h a l f of whom a r e non-DBMS u s e r s . Data C a t a l o g u e 2 s u p p o r t s a l a r g e number of p r e - d e f i n e d and u s e r - d e f i n e d e n t i t y t y p e s . The b a s i c e n t i t i e s s u p p o r t e d a r e : 1. Data e n t i t i e s such a s : a) ELEMENT b) GROUP c) RECORD d) FILE e) DATABASE 2. P r o c e s s e n t i t i e s such a s : a) MODULE b) PROGRAM c) SYSTEM 3. C o n c e p t u a l e n t i t i e s such a s : a) EXTERNAL b) TASK c) USER 4 . I n f o r m a t i o n i n t e r c h a n g e e n t i t i e s such a s : a) REPORT b) FORM 70 5 . D a t a b a s e s p e c i f i c e n t i t i e s s u c h as ( f o r IMS): a) SEGMENT b) SSA c) PSB The u s e r can a l s o s p e c i f y o t h e r e n t i t y t y p e s , a t t r i b u t e s f o r t h e s e e n t i t i e s and r e l a t i o n s h i p s t o o t h e r e n t i t i e s . The c o n c e p t u a l e n t i t y , EXTERNAL, can be u s e d t o d e s c r i b e an e x t e r n a l p r o c e s s i n g r e s o u r c e s u c h as a m i n i - c o m p u t e r , o r p r o c e d u r a l g u i d e . A t t r i b u t e s p r o v i d e d f o r EXTERNAL i n c l u d e RESPONSIBILITY, NAME, and LOCATION. Forms may be r e f e r e n c e d by MODULES, TASKS, SYSTEMS, and USERS and may r e f e r e n c e REPORTS o r d a t a e n t i t i e s . D a t a C a t a l o g u e 2 s u p p o r t s HIPO (IBM's H i e r a r c h i c a l I n p u t P r o c e s s i n g O u t p u t ) d o c u m e n t a t i o n m e t h o d o l o g y . T e c h n i q u e s f o r u s i n g e n t i t i e s s u c h as PROCESS, DATAFLOW and DATASTORE a r e p r o p o s e d by t h e v e n d o r . D a t a C a t a l o g u e 2 s u p p o r t s b o t h o n - l i n e and b a t c h d a t a i n p u t t h r o u g h a keyword b a s e d i n p u t l a n g u a g e . A f a c i l i t y f o r f i x e d f o r m a t b a t c h i n p u t b a s e d on p o s i t i o n a l p a r a m e t e r s can be s p e c i f i e d i n a CICS e n v i r o n m e n t . O n - l i n e e n t r y f e a t u r e s t u -t o r i a l p rompted e n t r y f o r i n e x p e r i e n c e d u s e r s . D a t a i n p u t i s f a c i l i t a t e d by a u t i l i t y w h i c h e x t r a c t s d a t a d e f i n i t i o n s from COBOL p r o g r a m s . An a d d i t i o n a l f e a t u r e i s t h e RENAME command w h i c h a l l o w s an e n t i t y o c c u r r e n c e s i m i l a r t o one a l r e a d y s t o r e d i n t h e d i c t i o n a r y t o be g e n e r a t e d . O u t p u t from D a t a C a t a l o g u e 2 can be p r o d u c e d b o t h o n - l i n e 71 and i n b a t c h , t h r o u g h f i v e o u t p u t i n t e r f a c e s : 1. O n - l i n e or b a t c h ad hoc q u e r i e s . T h e s e q u e r i e s use t h r e e b a s i c commands: a) COUNT - t o i d e n t i f y t h e number of o c c u r r e n c e s w h i c h s a t i s f y a q u e r y . b) L I S T - w h i c h r e t u r n s t h e names o f o c c u r r e n c e s . c ) SHOW - w h i c h r e t u r n s t h e a t t r i b u t e s of o c c u r r e n c e s . The q u e r y l a n g u a g e has a number o f m o d i f i e r s t o a l l o w a s o p h i s t i c a t e d s e a r c h r e q u e s t s . 2. R e p o r t s . T h e r e a r e f o u r t y p e s of r e p o r t s : a) CATALOG r e p o r t s w h i c h r e t u r n a l l a t t r i b u t e s s t o r e d f o r a s p e c i f i c e n t i t y o c c u r r e n c e or f o r t h e e n t i r e e n t i t y t y p e b) HIERARCHY r e p o r t s w h i c h show a l l components of an e n t i t y o c c u r r e n c e c) USAGE r e p o r t s w h i c h i d e n t i f y t h e r e f e r e n c e s t o an i t e m d) RELATIONAL r e p o r t s w h i c h p r o d u c e a c r o s s - r e f e r e n c e between a l l e n t i t i e s . The r e s u l t i n g r e p o r t can use 72 one of a number of names o r a l i a s e s s t o r e d f o r e a c h e n t i t y . 3. D a t a d e f i n i t i o n l a n g u a g e and program c o n t r o l b l o c k s a r e g e n e r a t e d f o r a number o f d a t a b a s e management s y s t e m s i n c l u d i n g IMS, DL/1-D0S/VS, TOTAL, ADABAS, MARK IV, IDMS, DMS1100, and S/2000. 4. Program d a t a d i v i s i o n s a r e g e n e r a t e d f o r COBOL, PL/1 and A s s e m b l e r . 5. Programs can c a l l t h e d a t a d i c t i o n a r y d u r i n g e x e c u t i o n t i m e t o e x t r a c t d a t a . S e c u r i t y i s p r o v i d e d by p a s s w o r d v a l i d a t i o n f o r u s e r s , and l e v e l of a u t h o r i t y f o r command e x e c u t i o n and d a t a a c c e s s . U s e r s c an be a s s i g n e d o w n e r s h i p t o s p e c i f i c e n t r i e s . 4.4 UCC-10 UCC-10 i s m a r k e t e d by U n i v e r s i t y Computing Company of D a l l a s , T e x a s . I t i s i n t e n d e d a s a s u p p o r t i n g t o o l t o t h o s e i n s t a l l a t i o n s u s i n g IBM's IMS or DL/1. I t i s w r i t t e n i n COBOL (90%) and A s s e m b l e r l a n g u a g e . UCC-10 has e i g h t b a s i c e n t i t i e s t o d e s c r i b e d a t a and p r o -c e s s e s . T h e r e a r e a l s o 13 a d d i t i o n a l e n t i t i e s u s e d i n an IMS 73 d a t a c o m m u n i c a t i o n s e n v i r o n m e n t t o d e s c r i b e c o m m u n i c a t i o n s and t e r m i n a l e n t i t i e s . The c o m m u n i c a t i o n s e n t i t i e s a l l o w r e l a -t i o n s h i p s t o be e s t a b l i s h e d between c o m m u n i c a t i o n s , d a t a , and p r o c e s s i n g e n t i t i e s and a r e u s e d by UCC-10 u t i l i t i e s t o g e n e r a t e IMS/DC s y s t e m s o p e r a t i o n s c o d e . The e i g h t b a s i c e n-t i t i e s u s e d by UCC-10 a r e : 1. F i e l d . UCC-10 u s e s f i e l d t o d e n o t e t h e i n d i v i s i b l e u n i t of d a t a . A f i e l d i s d e s c r i b e d by a t t r i b u t e s s u c h as FLN (name), PIC (COBOL-type p i c t u r e ) , JUST ( j u s t i f i c a t i o n ) , and CBLN (COBOL name). R e l a t i o n s h i p s t o segments (SGN), and p r o g ram (PGN) a r e m a i n t a i n e d . 2. L i s t . UCC-10 u s e s t h i s a t t r i b u t e t o i d e n t i f y s e c o n d a r y i n d e x e s i n t h e d a t a b a s e . A t t r i b u t e s o f l i s t s a r e L I S T ( w h i c h i s t h e name) and TTL (a d e s c r i p t i o n o f t h e l i s t ) . R e l a t i o n s h i p s a r e m a i n t a i n e d w i t h segments (SGN) and f i e l d s ( F L D ) . 3. Segment. The segment e n t i t y c an be u s e d as an IMS s e g -ment o r as a r e c o r d i n a c o n v e n t i o n a l f i l e e n v i r o n m e n t . A t t r i b u t e s i n c l u d e SGN (segment name), MAXB ( t h e l e n g t h of t h e segment i n b y t e s ) , MINB ( t h e minimum s i z e i f i t i s a v a r i a b l e l e n g t h r e c o r d ) , and I M S - r e l a t e d a t t r i -b u t e s . Some of t h e s e a t t r i b u t e s d e f i n e t h e p o s i t i o n o f t h e segment w i t h i n t h e IMS h i e r a r c h y . F o r example, s e g -ments c a n be l o g i c a l p a r e n t s and d e f i n e l o g i c a l c h i l d r e n 7 4 (LCN) and t h e d a t a b a s e w i t h i n w h i c h t h e y a r e l o g i c a l p a r e n t s ( L D B ) . D a t a S e t Group. T h i s e n t i t y i s u s e d by UCC-10 t o d e f i n e a d a t a s e t g r o u p i n t h e IMS e n v i r o n m e n t o r a f i l e i n t h e c o n v e n t i o n a l d a t a s t o r a g e e n v i r o n m e n t . A t t r i b u t e s i n c -l u d e name (DSN), i n p u t o r o u t p u t b l o c k s i z e (BLK1 o r BLK2), d e v i c e t y p e (DEV), and o t h e r OS o r IMS a t t r i -b u t e s . D a t a b a s e . T h i s e n t i t y i s u s e d t o d e f i n e IMS d a t a b a s e s as w e l l a s OS f i l e s . I t s a t t r i b u t e s , s u c h a s DL/1 (wh i c h i d e n t i f i e s i t as a DL/1 d a t a b a s e ) , and RMOD (wh i c h i d e n t i f i e s t h e name o f a r a n d o m i z i n g r o u t i n e f o r a HDAM d a t a b a s e ) , i d e n t i f y a d d i t i o n a l p a r a m e t e r s f o r t h e g e n e r a t i o n of a DL/1 o r IMS d a t a b a s e . The r e l a t i o n s h i p s t o p r ograms and d a t a s e t s p o s i t i o n t h i s e n t i t y a s a l o -g i c a l c o n n e c t i o n . T h e r e a r e no r e l a t i o n s h i p s between programs and d a t a s e t s . M o d u le. The module i s t h e l o w e s t l e v e l of p r o c e s s e n t i -t y . A t t r i b u t e s o f t h e module a r e MDN ( t h e module name), LANG ( t h e s o u r c e l a n g u a g e of t h e m o d u l e ) , PGMR ( t h e p r o -grammer o r a n a l y s t r e s p o n s i b l e f o r t h e m o d u l e ) , and TTL (a 30 c h a r a c t e r d e s c r i p t i o n ) . M o d u l e s c a n be l i n k e d t o p r o g r a m s . 75 7. T r a n s a c t i o n . T h i s e n t i t y i s us e d t o i d e n t i f y an o n - l i n e c o n v e r s a t i o n i n p u t r e c o r d . A t t r i b u t e s d e a l w i t h IMS/DC h a n d l i n g of t h e t r a n s a c t i o n i n p u t . They i n c l u d e CLAS, t h e IMS message r e g i o n c l a s s ; IQRY, whether o r n o t t h e t r a n s a c t i o n w i l l m o d i f y an IMS d a t a b a s e ; SPAL, t h e s c r a t c h pad a r e a l o c a t i o n ; and TYPE, whether t h e t r a n s a -c t i o n i s p r o c e s s e d i n r e a l t i m e and g e n e r a t e s an imme-d i a t e r e s p o n s e . T r a n s a c t i o n s c a n be l i n k e d t o a p r o -gram. 8. Prog r a m . UCC-10 s u p p o r t s p r o g ram e n t i t i e s w i t h a t t r i -b u t e s s u c h a s PGN ( t h e name of t h e p r o g r a m ) , LANG ( t h e s o u r c e l a n g u a g e ) , and TYPE. A program c a n be one o f f o u r t y p e s : a DL/1 p r o g r a m w h i c h can p r o c e s s messages i n b a t c h , an o n - l i n e mode, a DL/1 p r o g r a m w h i c h does not p r o c e s s messages and c a n o n l y run i n b a t c h , and a p r o -gram w h i c h does not i n t e r f a c e w i t h DL/1. UCC-10 s t o r e s r e l a t i o n s h i p s t o o t h e r d a t a e n t i t i e s , s u c h as FIELD, Segments and D a t a b a s e s i n t h e PROGRAM e n t i t y . I n p u t t o UCC-10 can be done i n o n - l i n e or b a t c h mode. I n p u t s t a t e m e n t s a r e a m i x t u r e o f f r e e and f i x e d f o r m a t s t a t e -ments, where keywords a r e u s e d t o i d e n t i f y t h e d a t a i n p u t . O n - l i n e d a t a e n t r y t r a n s a c t i o n s i n c l u d e q u e r i e s and can be p r o c e s s e d t h r o u g h b a t c h u p d a t e o r e x e c u t e d i m m e d i a t e l y . UCC-10 has u t i l i t i e s t o a l l o w d a t a d e f i n i t i o n s t o be e x t r a c t e d from e x i s t i n g IMS o r DL/1 d a t a b a s e d e f i n i t i o n s , as w e l l as 76 from COBOL and PL / 1 I/O a r e a s . UCC - 1 0 has a c o m p l e t e s e t of r e p o r t s f o r e a c h e n t i t y sup-p o r t e d . P a r a m e t e r s i n t h e REP command a l l o w t h e u s e r t o s p e -c i f y t h e name o f t h e e n t i t y o c c u r r e n c e , t h e t y p e of a t t r i b u t e s and r e l a t i o n s h i p s ( c a l l e d CONNECTIONS i n U C C - 1 0 ) , and t h e un-d e r l y i n g s t r u c t u r e ( w h i c h may be where-used o r c o n t a i n s r e l a -t i o n s h i p s ) t o be o u t p u t . G l o s s a r y r e p o r t s o u t p u t g e n e r a l d e s -c r i p t i o n s s t o r e d i n t h e TEXT a t t r i b u t e f o r s e l e c t e d o c c u r -r e n c e s i n t h e d i c t i o n a r y . Keyword i n c o n t e x t r e p o r t s (KWIC) a r e p r o v i d e d f o r words s t o r e d i n t h e e l e m e n t name, t i t l e , COBOL, o r PL / 1 name f i e l d s o r i n t h e d e s c r i p t i o n t e x t . U CC - 1 0 has u t i l i t i e s t o g e n e r a t e IMS s t a t e m e n t s f o r d a t a -base g e n e r a t i o n , p r o g r a m I/O a r e a s , p r o g ram d a t a b a s e c a l l s (SSA) and t o s u p p o r t t h e d a t a c o m m u n i c a t i o n s f a c i l i t i e s of IMS. UCC - 1 0 a l s o g e n e r a t e s COBOL, PL / 1 and A s s e m b l e r I/O a r e a s , and T e r m i n a l S e c u r i t y m a i n t e n a n c e t r a n s a c t i o n s . UCC - 1 0 i s d e s i g n e d t o s u p p o r t IMS o r DL/1 i n an OS o r DOS e n v i r o n m e n t . As i s o b v i o u s from t h e e n t i t y t y p e s , t h i s d a t a d i c t i o n a r y would n o t f u n c t i o n a s w e l l i n a non-IMS o r non-DL/ 1 e n v i r o n m e n t . S e c u r i t y f e a t u r e s a r e im p l e m e n t e d t h r o u g h t h e use o f IMS t e r m i n a l s e c u r i t y c o d e s . T e r m i n a l s c an be d e s i g -n a t e d a s r e a d o n l y (HFR) o r r e a d and w r i t e (HFD). 77 4.5 IDD IDD i s a d a t a d i c t i o n a r y d e v e l o p e d by C u l l i n a n e D a t a b a s e S y s t e m s , as a f r o n t end t o t h e i r IDMS d a t a b a s e . IDD u t i l i z e s IDMS ( w h i c h i s a CODASYL f o r m a t d a t a b a s e ) t o s t o r e i t s i n f o r -m a t i o n . IDMS a u t o m a t i c a l l y u p d a t e s t h e d i c t i o n a r y when u s e r s d e f i n e t h e d a t a b a s e schema. IDD i s r e p o r t e d t o have o v e r 200 i n s t a l l a t i o n s . E n t i t y s u p p o r t i n IDMS i s e x t e n s i v e . T h e r e a r e e i g h t b a s i c d a t a p r o c e s s i n g e n t i t i e s : 1 . SYSTEM 2. PROGRAM 3 . MODULE 4. ENTRY POINT 5. F I L E 6 . RECORD 7. ELEMENT 8. USER T h e r e a r e a l s o n i n e t e l e p r o c e s s i n g e n t i t i e s w h i c h a l l o w d o c u m e n t a t i o n of o n - l i n e s y s t e m s . These e n t i t i e s may o n l y be us e d i f IDMS-DC i s i n s t a l l e d . As many o f t h e r e l a t i o n s h i p s 78 and a t t r i b u t e v a l u e s a r e a u t o m a t i c a l l y g e n e r a t e d by IDMS-DC c o m p i l e r s . T h e s e e n t i t i e s a r e : 1. PANEL 2. MAP 3. LINE 4. PHYSICAL TERMINAL 5. LOGICAL TERMINAL 6. DESTINATION 7. QUEUE 8. TASK 9. MESSAGE F i n a l l y , IDD a l l o w s f o r two " m e t a - e n t i t i e s " w h i c h a l l o w u s e r s t o d e f i n e a t t r i b u t e s o f e n t i t i e s and c l a s s e s or t y p e s o f a t t r i b u t e s . They a r e : 1. CLASS 2. ATTRIBUTE A l l s t a n d a r d e n t i t i e s e x c e p t f o r e n t r y p o i n t can have r e l a t i o n s h i p s w i t h e n t i t i e s o f t h e same t y p e . SYSTEMS, f o r example, c a n be r e l a t e d t o o t h e r SYSTEMS, ELEMENTS t o o t h e r ELEMENTS and so on. T h i s a l l o w s f o r s t r u c t u r e s s u c h as p r o -grams, subprograms o r s y s t e m s and s u b s y s t e m s t o be r e c o r d e d . 7 9 In a d d i t i o n , IDD p r o v i d e s f o r a t t r i b u t e s w h i c h i d e n t i f y r e l a t i o n s h i p s between e n t i t i e s . E xamples a r e : SOURCE ENTITY TARGET ENTITY RELATIONSHIP ATTRIBUTE USER SYSTEM OF SYSTEM SYSTEM USER RESPONSIBLE PROGRAM USER PREPARED, RESPONSIBLE PROGRAM SYSTEM WITHIN SYSTEM PROGRAM MODULE MODULE USED PROGRAM RECORD RECORD COPIES F I L E USER PREPARED, USER-IS RECORD RECORD USER F I L E PREPARED, USER-IS WITHIN F I L E , i n c l u d e s KEY R e l a t i o n s h i p s may be d e f i n e d by u s e r s t h r o u g h t h e " R e l a t i o n a l Key I S " s t a t m e n t . R e l a t i o n s h i p s between r e c o r d s and e l e m e n t s a r e p r o v i d e d by t h e RECORD ELEMENT s u b s t a t e m e n t w h i c h a l l o w s e l e m e n t s or s t r u c t u r e s of e l e m e n t s t o be r e l a t e d t o a R e c o r d . The RECORD ELEMENT s u b s t a t e m e n t a l s o a l l o w s t h e ELEMENT t o be r e d e f i n e d , i . e . PICTURE, VALUE, INDEX KEY and o t h e r a t t r i b u t e s can be c h a n g e d . The ELEMENT d e f i n i t i o n , ho-wever, w i l l n ot change i n t h e d i c t i o n a r y . IDD a l s o a l l o w s t h e u s e r t o d e f i n e ELEMENT-RECORD r e l a t i o n s h i p s by u s i n g a COBOL-80 t y p e s u b s t a t e m e n t . T h i s a l l o w s r e g u l a r COBOL s y n t a x t o be u s e d t o s e t up RECORDS and RECORD-ELEMENT r e l a t i o n s h i p s . Any ELEMENT r e f e r r e d t o w h i c h i s not on t h e d i c t i o n a r y w i l l a l s o be s e t up. ; The t e l e p r o c e s s i n g e n t i t i e s , PANEL and MAP, a l l o w f o r t h e d o c u m e n t a t i o n of o n - l i n e s c r e e n s and r e l a t i o n s h i p s between s y s t e m s and s c r e e n s . The D a t a D i c t i o n a r y D e f i n i t i o n Language c o m p i l e r d o e s not b u i l d r e l a t i o n s h i p s between MAPs and RECORDS or ELEMENTS. T h i s i s done by t h e IDMS-DC mapping c o m p i l e r t h r o u g h t h e USING RECORDS s t a t e m e n t . IDD o n l y r e c o r d s t h e e x i s t e n c e o f PANELS and MAPS and r e l a t i o n s h i p s from PROGRAMS or SYSTEMS t o MAPS, and f r o m MAPS t o PANELS. The IDD MESSAGE e n t i t y a l l o w s f o r messages t o be s t o r e d w i t h i n t h e s y s t e m . Messages can be e r r o r messages, or o p e r a -t o r c o n t r o l messages. The MESSAGE e n t i t i e s s u p p o r t e d by IDMS-DC a r e e r r o r messages. Message t e x t , d e s t i n a t i o n , and s e v e r i -t y code c a n be s t o r e d . IDMS-DC u s e s MESSAGE e n t i t i e s a t e x e -c u t i o n t i m e . The r e m a i n i n g t e l e p r o c e s s i n g e n t i t i e s , LINE, PHYSICAL TERMINAL, LOGICAL TERMINAL, DESTINATION, QUEUE and TASK a r e u s e d t o document an o n - l i n e e n v i r o n m e n t . TASKS a r e t e l e p r o c e s s i n g work u n i t s . T a s k s INVOKE p r o -grams WITHIN s y s t e m s . TASKS can be a s s i g n e d a SECURITY CLASS and a TASK PRIORITY. 81 QUEUES documents a g r o u p of t a s k s h a n d l e d by t h e t e l e p r o -c e s s i n g s y s t e m . T h i s i n s t r u c t s t h e IDMS-DC s y s t e m t o a l l o w a number (THRESHOLD) t o be r e a c h e d b e f o r e a t a s k (THRESHOLD TASK) i s i n v o k e d w i t h i n a SYSTEM. A DESTINATION documents a c l u s t e r o f t e r m i n a l s o r u s e r s , t o whom messages, from s y s t e m s o r t h e o p e r a t o r , would be s e n t . R e l a t i o n s h i p s t o s y s t e m s (WITHIN SYSTEM), u s e r s (USER IS) and t e r m i n a l s (LOGICAL TERMINAL) a r e m a i n t a i n e d . A LOGICAL TERMINAL e s t a b l i s h e s a r e l a t i o n s h i p between SYSTEMS and PHYSICAL TERMINALS o r d e v i c e s . The l o g i c a l t e r -m i n a l r e l a t i o n s h i p c a n c r e a t e l i n k s between more t h a n one s y s -tem, t o a u n i q u e p h y s i c a l t e r m i n a l . The PHYSICAL TERMINAL e n t i t y documents t h e LINE e a c h SYSTEM w i l l use t o a c c e s s t h e t e r m i n a l . I t a l s o e s t a b l i s h e s t h e d e v i c e t y p e . The LINE e n t i t y d e f i n e s t h e t y p e o f t e l e c o m m u n i c a t i o n l i n e s w h i c h e x i s t i n a d a t a c o m m u n i c a t i o n s e n v i r o n m e n t . The LINE e n t i t y has t h e a b i l i t y t o document LINE-SYSTEM r e l a t i o n -s h i p s (WITHIN SYSTEM). CLASSES and ATTRIBUTE e n t i t i e s can be u s e d f o r two main p u r p o s e s . F i r s t t o more c o m p l e t e l y d e f i n e an e n t i t y w h i c h a l r e a d y e x i s t s . F o r example, a CLASS "Department" can be a d d e d w i t h ATTRIBUTES " A c c o u n t i n g , M a r k e t i n g , P a y r o l l " . T h e s e can t h e n be u s e d i n f u r t h e r d e f i n i n g t h e e n t i t y USER. Second, 8 2 t h e CLASS and ATTRIBUTE can be u s e d t o s i m u l a t e o t h e r e n t i -t i e s . T h i s i s p o s s i b l e b e c a u s e ATTRIBUTES c a n be n e s t e d . T h a t i s , ATTRIBUTES can c o n t a i n c l a s s e s w h i c h a l s o have ATTRIBUTES. F o r example we c a n d e f i n e t h i s s t r u c t u r e : ADD CLASS NAME IS DEPARTMENT ATTRIBUTES ARE AUTOMATIC ADD CLASS NAME IS DIVISION ATTRIBUTES ARE AUTOMATIC ADD CLASS NAME IS CORPORATION ATTRIBUTES ARE AUTOMATIC ADD ATTRIBUTE RESEARCH WITHIN DEPARTMENT ADD ATTRIBUTE ADMINISTRATION WITHIN DEPARTMENT ADD ATTRIBUTE CUSTOMER RECORDS WITHIN DEPARTMENT ADD ATTRIBUTE BELL NORTHERN WITHIN DIVISION DEPARTMENT IS RESEARCH DEPARTMENT IS ADMINISTRATION ADD ATTRIBUTE BELL CANADA WITHIN CORPORATION DIVISION IS BELL NORTHERN DEPARTMENT IS HEAD OFFICE DEPARTMENT IS CUSTOMER RECORDS T h i s s t r u c t u r e d e f i n e s t h e h y p o t h e t i c a l o r g a n i z a t i o n a l 83 h i e r a r c h y of B e l l Canada. In t h i s example, B e l l Canada i s a c o r p o r a t i o n who has one d i v i s i o n , B e l l N o r t h e r n ( w h i c h i s a r e s e a r c h a rm). T h i s d i v i s i o n c o n t a i n s two d e p a r t m e n t s , RESEARCH and ADMINISTRATION. The ATTRIBUTES ARE AUTOMATIC p h r a s e a l l o w s t h e u s e r t o i d e n t i f y new a t t r i b u t e names and v a l u e s by k e y i n g them i n d u r i n g d e f i n i t i o n . T h i s i s t h e c a s e w i t h DEPARTMENT IS HEAD O F F I C E . I n p u t t o IDD i s t h r o u g h a c o m p r e h e n s i v e u s e r l a n g u a g e , and o n l y i n b a t c h mode. The d a t a d i c t i o n a r y has i n t e r f a c e s t o COBOL, PL/1, RPG and BAC u t i l i t i e s t o a l l o w d a t a b a s e usage (IDMS o n l y ) t o be c a p t u r e d . In a d d i t i o n , schemas and s u b s c h e -mas a d d e d -to t h e IDMS d a t a b a s e a u t o m a t i c a l l y u p d a t e t h e d a t a d i c t i o n a r y . Programs w h i c h use d e f i n i t i o n s s t o r e d i n t h e d a t a d i c t i o n a r y a u t o m a t i c a l l y c r e a t e d i c t i o n a r y o c c u r r e n c e s when p r o c e s s e d by t h e DML ( d a t a m a n i p u l a t i o n l a n g u a g e ) i n t e r f a c e . O u t p u t from IDD c a n be t h r o u g h t h e D i c t i o n a r y / D i r e c t o r y R e p o r t e r (DDR), t h r o u g h u s e r - d e f i n e d r e p o r t s w h i c h use t h e CULPRIT r e p o r t l a n g u a g e or OLQ (On L i n e Q u e r y ) , or t h r o u g h u s e r - w r i t t e n r e p o r t p rograms a c c e s s i n g t h e IDMS b a s e d IDD d a t a d i c t i o n a r y t h r o u g h r e g u l a r d a t a b a s e a c c e s s r o u t i n e s . The DDR i s a s e t of p r e d e f i n e d CULPRIT r e p o r t p a r a m e t e r s s t o r e d i n t h e d a t a d i c t i o n a r y . T h e r e a r e 66 s t a n d a r d r e p o r t s w h i c h : 1. L i s t a l l a t t r i b u t e s of e a c h s t a n d a r d e n t i t y t y p e . 2 . L i s t , i n summary, a l l o c c u r r e n c e s i n t h e e n t i t y t y p e 84 (name o f e n t i t y , d e s c r i p t i o n ) . 3. L i s t s a l l a t t r i b u t e s f o r t h o s e e n t i t y o c c u r r e n c e s w h i c h have been r e q u e s t e d by a "key 'name'" s t a t e m e n t . Key u s u a l l y r e f e r s t o t h e name o f t h e e n t i t y t y p e . 4. R e p o r t c r o s s r e f e r e n c e s between: f i l e s and r e c o r d s f i l e names and synonyms r e c o r d names and schemas e l e m e n t - synonyms and g r o u p s e l e m e n t names and e l e m e n t d e s c r i p t i o n s e l e m e n t d e s i g n a t o r c l a s s e s and e l e m e n t names f i l e s and programs IDMS s e t s and programs r e c o r d s and programs a r e a s and programs e l e m e n t s and p r o g r a m s . 5. O u t p u t s o u r c e code o n t o c a r d s o r i n t o a d i s k f i l e . T h e r e a r e a l s o 32 r e p o r t s w h i c h a r e a v a i l a b l e t o u s e r s o f IDMS/DC. Th e s e r e p o r t s d e s c r i b e : 1 . The IDMS/DC network w h i c h c o n s i s t s o f l i n e s and p h y s i c a l and l o g i c a l t e r m i n a l s . T h r e e r e p o r t s a r e p r o v i d e d : 85 a) Network D e s c r i p t i o n by L i n e b) Network D e s c r i p t i o n by P h y s i c a l T e r m i n a l c )• Network D e s c r i p t i o n by L o g i c a l T e r m i n a l . 2 . The p r o g r a m s , t a s k s , q ueues, d e s t i n a t i o n s , u s e r s , and s y s t e m s w i t h i n an o p e r a t i o n a l IDMS/DC s y s t e m . 3 . Messages and d e v i c e s i n t h e s y s t e m . 4. S c r e e n s ( c a l l e d PANELS), MAPS, w h i c h a r e r e l a t i o n s h i p s between PANELS and s y s t e m s , and RECORDS or ELEMENTS w h i c h a p p e a r on t h e PANELS. Because t h e DDR u s e s p r e - d e f i n e d CULPRIT p a r a m e t e r i n p u t t o g e n e r a t e s t a n d a r d r e p o r t s , t h e u s e r can m o d i f y t h e s e p a r a -m e t e r s w h i c h a r e s t o r e d as MODULE o c c u r r e n c e s i n t h e d a t a d i c -t i o n a r y . In t h i s way, t h e u s e r can r e s t r i c t t h e e x t r a c t i o n o f e n t i t y o c c u r r e n c e s t o t h o s e he/she d e s i r e s , m o d i f y a s o r t s e -q u e n c e , o r add a d d i t i o n a l e n t i t i e s o r a t t r i b u t e s t o a r e p o r t . The u s e r can a l s o w r i t e h i s / h e r own CULPRIT r e p o r t s . The d a t a d i c t i o n a r y i s an IDMS d a t a b a s e , t h e r e f o r e t h e d a t a d i c t i o n a r y ' s schema i s s t o r e d w i t h i n t h e d a t a d i c t i o n a r y and can be u s e d by CULPRIT t o e x t r a c t i n f o r m a t i o n . T h i s same schema c a n be u s e d t o a l l o w p rograms w r i t t e n i n COBOL, P L / 1 , FORTRAN and A s s e m b l e r l a n g u a g e s , w h i c h have i n -t e r f a c e s , t o IDMS, t o e x t r a c t d i c t i o n a r y d a t a f o r r e p o r t i n g o r any o t h e r p u r p o s e . 86 S e c u r i t y i n IDD i s p r o v i d e d by: 1. The s p e c i f i c a t i o n o f USERS who a r e a s s i g n e d p a s s w o r d s . 2. The s p e c i f i c a t i o n o f a USER who i s g i v e n t h e power t o t u r n t h e g l o b a l SECURITY a t t r i b u t e ON or OFF. 3. The s p e c i f i c a t i o n of a RESPONSIBLE code f o r t h e o c c u r -r e n c e . The p o s s i b l e a l t e r n a t i v e s a r e : a) DEFINITION - T h i s a l l o w s t h e u s e r named t o m o d i f y o r d e l e t e t h e e n t i t y o c c u r r e n c e b) RESPONSIBLE w i t h o u t any p a r a m e t e r s , w h i c h w i l l de-f a u l t t o DEFINITION. O t h e r r e s p o n s i b i l i t y c o d e s , CREATION, UPDATE and DELETION, a r e not u s e d by IDD, but a r e a v a i l a b l e f o r d o c u m e n t a t i o n . 4. The s p e c i f i c a t i o n of IDMS a n d / o r DC a u t h o r i t y (AUTHORITY IS IDMS/DC), w h i c h p e r m i t s t h e u s e r t o m o d i f y a n d / o r d e l e t e schemas and subschemas, or o t h e r IDMS f u n c t i o n s i f IDMS i s s p e c i f i e d , and m o d i f y o r d e l e t e t h e t e l e p r o -c e s s i n g e n t i t i e s i f DC i s s p e c i f i e d . T h e r e a r e a number o f o t h e r s y s t e m s on t h e market i n c l u -d i n g some w h i c h have been r e c e n t l y i n t r o d u c e d . D o c u m e n t a t i o n , 87 beyond p r o m o t i o n a l l i t e r a t u r e , was n o t a v a i l a b l e f o r t h e s e s y s t e m s . However, t h e a u t h o r would l i k e t o m e n t i o n two s y s -tems, CINCOM's D a t a C o n t r o l S ystem and I C L ' s DDS b e c a u s e of t h e i r s t a t e - o f - t h e - a r t d e s i g n . F e a t u r e s r e p o r t e d a r e t a k e n d i r e c t l y f r o m t h e m a n u f a c t u r e r ' s l i t e r a t u r e . CINCOM DATA CONTROL SYSTEM T h i s s y s t e m i s d i v i d e d i n t o 4 s u b - s y s t e m s : 1. The I n t e r a c t i v e D a t a D i c t i o n a r y . 2. The System D e s i g n F a c i l i t y . 3. The Programmer Work S t a t i o n . 4. The D a t a S e c u r i t y System. The d a t a d i c t i o n a r y a l l o w s i n p u t from o n - l i n e s c r e e n s w h i c h may be a p p l i e d t o t h e d a t a d i c t i o n a r y i m m e d i a t e l y or b a t c h e d . M a i n t e n a n c e of d a t a d e f i n i t i o n s c a n a l s o be done on-l i n e . The s y s t e m a l s o a l l o w s f o r e x t r a c t i o n of d a t a d e f i n i -t i o n s f r o m programs and d a t a b a s e s . O u t p u t i s t h r o u g h o n - l i n e q u e r y and b a t c h r e p o r t i n g . Q u e r i e s may be c a t a l o g u e d and a r e e x p r e s s e d i n a " r e l a t i o n a l l a n g u a g e " . O n - l i n e q u e r y r e s u l t s c a n be r o u t e d t o t h e p r i n -t e r . Changes t o d a t a d i v i s i o n s o f programs w h i c h a r e h e l d by t h e d i c t i o n a r y , a u t o m a t i c a l l y m o d i f y copy l i b r a r i e s so t h a t p r o g r a m s need o n l y be r e c o m p i l e d t o e x e c u t e . 88 D a t a C o n t r o l S ystem s u p p o r t s d a t a p r o c e s s i n g and u s e r e n v i r o n m e n t e n t i t i e s s u c h as s y s t e m s , p r o g r a m s , m o d u l e s , d a t a -b a s e s , f i l e s , e l e m e n t s , s o u r c e documents, t e r m i n a l s c r e e n s , r e p o r t s , u s e r s , d e p a r t m e n t s , and d i v i s i o n s . The System D e s i g n F a c i l i t y a l l o w s t h e a n a l y s t t o use d a t a d i c t i o n a r y i n f o r m a t i o n t o c r e a t e d a t a - f l o w d i a g r a m s and l o g i -c a l d a t a s t r u c t u r e s and t r a n s l a t e them i n t o a p h y s i c a l d a t a -base d e s i g n . The Programmer Work S t a t i o n p r o v i d e s programmers w i t h f u l l s c r e e n e d i t c a p a b i l i t y , l i b r a r y a c c e s s (DCS l i b r a r i e s , PANVALET and LIBRARIAN), and an i n t e r f a c e t o t h e d a t a d i c -t i o n a r y t o e x t r a c t d a t a d i v i s i o n f o r m a t s and g e n e r a t e code f o r d a t a b a s e a c c e s s . Programs can be c o m p i l e d and e x e c u t e d on-l i n e w i t h r e s u l t s r o u t e d t o t h e t e r m i n a l or a p r i n t e r . DCS D a t a . S e c u r i t y p r o v i d e s e x e c u t e t i m e s e c u r i t y c h e c k i n g a t b o t h t h e f i l e and e l e m e n t l e v e l . A l l u s e r s of DCS a r e s c r e e n e d by p a s s w o r d i n t e r r o g a t i o n a t s i g n o n , t o e n s u r e t h a t t h e u s e r ' s p r o f i l e matches t h e t a s k s p e r f o r m e d . DCS i s p a r t of t h e T I S s y s t e m m a r k e t e d by CINCOM, w h i c h e s p o u s e s a c o n s i s -t e n t , d i c t i o n a r y b a s e d view of d a t a p r o c e s s i n g , d a t a b a s e mana-gement and c o m m u n i c a t i o n s management. 89 ICL DDS The ICL DDS s y s t e m i s i m p o r t a n t b e c a u s e o f t h e f o r m a l i z a -t i o n o f a model w h i c h i n c l u d e s b o t h p h y s i c a l d a t a and p r o -c e s s e s a s w e l l a s l o g i c a l d a t a and p r o c e s s e s , and r e l a t i o n -s h i p s between them. D a t a i n p u t and o u t p u t a r e o n - l i n e or i n b a t c h . I n p u t i s v i a keywords and t h e DDL has commands s u c h as INSERT and REPLACE, o u t p u t commands s u c h a s DISPLAY, SELECT, L I S T and PRINT, a l o n g w i t h s e l e c t i o n s t a t e m e n t s FOR, WITH and ALL p r o m i s e a c o m p l e t e and s i m p l e t o use s y s t e m . E n t i t i e s a r e b r o k e n i n t o 4 main t y p e s : 1. COMPUTER DATA: a) V . F I L E b) F I L E c) RECORD d) GROUP e) ITEM f ) AREA g) SCHEMA h) SUBSCHEMA i ) SET DDS u s e s t h e IDMS d a t a b a s e w h i c h i s a CODASYL s y s t e m . T h i s 90 a c c o u n t s f o r e n t i t i e s f t h r o u g h i . 2 . COMPUTER PROCESSES: a) SYSTEM b) PROGRAM c) MODULE 3. REAL WORLD DATA: a) ATTRIBUTE b) ENTITY c ) RELATIONSHIP 4. REAL WORLD PROCESS MODEL: a) EVENT b) OPERATION. S p e c i a l e n t i t i e s a l l o w f o r l i n k s between t h e s e e n t i t y t y p e s . T h e s e e n t i t i e s , DPROC, DMAP, PMAP, DUSE, a l l o w f o r t h e e x p l i c i t mapping o f c o n c e p t u a l e n t i t i e s t o i m p l e m e n t a t i o n e n-t i t i e s . DPROC maps between c o n c e p t u a l p r o c e s s e s and c o n c e p t u a l d a t a e n t i t i e s u s i n g a t t r i b u t e s s u c h a s CREATES, DELETES, UPDATES, w h i c h d e s c r i b e t h e e f f e c t s of OPERATIONS on E N T I T I E S . 91 DUSE maps between i m p l e m e n t a t i o n d a t a and i m p l e m e n t a t i o n p r o c e s s e s . A t t r i b u t e s s u c h as PROCESS, CREATES, DELETES, READS and UPDATES a r e documented f o r PROGRAM-FILE, PROGRAM-RECORD and SYSTEM-FILE r e l a t i o n s h i p s , among o t h e r s . DMAP maps between c o n c e p t u a l d a t a and i m p l e m e n t a t i o n d a t a . T h r o u g h t h i s e n t i t y , E N T I T Y - F I L E , ENTITY-GROUP and RELATIONSHIP-ITEM l i n k s c a n be made. A t t r i b u t e s u s e d i n c l u d e CONCEPTUAL-DATA and IMPLEMENTATION-DATA. T h i s a l l o w s , f o r example, an e n t i t y s u c h a s EMPLOYEE t o be l i n k e d t o t h e EMPLOYEE r e c o r d o r t h e AGE a t t r i b u t e t o be l i n k e d t o t h e EMP-AGE i t e m . F i n a l l y , PMAP maps o p e r a t i o n s t o programs and s y s t e m s , l i n k i n g b u s i n e s s f u n c t i o n s t o s y s t e m s and pro g r a m s w h i c h imp-lem e n t them. A t t r i b u t e s m a i n t a i n e d i n c l u d e CONCEPTUAL-PROCESS and IMPLEMENTATION-PROCESS. The a u t h o r b e l i e v e s t h a t t h e d i r e c t i o n t a k e n by t h e s e and o t h e r s i m i l a r s y s t e m s i n i m p l e m e n t i n g d a t a d i c t i o n a r i e s t h a t a d d r e s s b o t h t h e c o n c e p t u a l v i e w o f d a t a and p r o c e s s e s and t h e need t o i n t e g r a t e t h e d a t a d i c t i o n a r y i n t o a c o m p r e h e n s i v e t o o l f o r a l l u s e r s of d a t a , i s an i n d i c a t i o n o f t h e m a t u r i n g o f d a t a d i c t i o n a r y s y s t e m s . 92 CHAPTER 5 A DATA DICTIONARY IN AN ENTERPRISE ENVIRONMENT  O v e r v i e w The p r e v i o u s c h a p t e r s have examined d a t a d i c t i o n a r i e s f r o m a s t r u c t u r a l p e r s p e c t i v e . We have i d e n t i f i e d a model f o r l o o k i n g a t d a t a d i c t i o n a r i e s w h i c h c l a s s i f y t h e c o n t e n t s . In t h i s c l a s s i f i c a t i o n , a d a t a d i c t i o n a r y i t s e l f c o n t a i n s o n l y d a t a d e s c r i p t i o n s . D a t a e l e m e n t l o c a t i o n i n f o r m a t i o n i s c o n -t a i n e d i n t h e d a t a d i r e c t o r y , w h i c h a l s o documents p r o c e s s d a t a and p r o v i d e s r e l a t i o n s h i p s between d a t a e l e m e n t s and p r o -c e s s e s . D a t a p r o c e s s i n g i n f o r m a t i o n , t h e p h y s i c a l a t t r i b u t e s of d a t a s t o r a g e and p r o g r a m e x e c u t i o n , a r e c o n t a i n e d i n t h e d a t a r e s o u r c e d i c t i o n a r y . The f i n a l l e v e l o f i n f o r m a t i o n a b o u t d a t a and p r o c e s s e s i s t h a t w h i c h c o n c e r n s t h e c o n c e p t u a l v i e w of t h e e n t e r p r i s e . T h i s l e v e l we have c a l l e d t h e metada-t a d i c t i o n a r y . In a d d i t i o n t o d e v e l o p i n g a s t r u c t u r e f o r d i c t i o n a r y s o f -t w a r e , we have i d e n t i f i e d t h o s e i n d i v i d u a l s i n an o r g a n i z a t i o n who would most l i k e l y u t i l i z e t h e d a t a d i c t i o n a r y , and t h e f u n c t i o n s p e r f o r m e d w h i c h w o u l d u t i l i z e t h e m e t a d a t a d i c -t i o n a r y . In e x a m i n i n g s o f t w a r e p a c k a g e s w h i c h a r e o f f e r e d by 93 v a r i o u s v e n d o r s , we have i d e n t i f i e d f u n c t i o n s and f e a t u r e s w h i c h a r e c o m m e r c i a l l y a v a i l a b l e i n d a t a d i c t i o n a r y p a c k a g e s . The m a j o r i t y of d a t a d e s c r i p t i o n s , d a t a l o c a t i o n and some me-t a d a t a i n f o r m a t i o n i s a v a i l a b l e i n c o m m e r c i a l p a c k a g e s . j.-The a v a i l a b i l i t y o f i n t e r f a c e s between d a t a d i c t i o n a r i e s , . p r o -grams, and d a t a b a s e management sytems r e p r e s e n t some of t h e f u n c t i o n s p e r f o r m e d by t h e d a t a r e s o u r c e d i c t i o n a r i e s . T h i s c h a p t e r w i l l f o c u s on management t o p i c s w h i c h w i l l most c e r t a i n l y a r i s e when an o r g a n i z a t i o n c o n s i d e r s t h e i m p l e -m e n t a t i o n o f a m e t a d a t a d i c t i o n a r y . T h i s c h a p t e r w i l l r e v i e w some of t h e major q u e s t i o n s an o r g a n i z a t i o n w i l l have and w i l l p r o v i d e some answers t o t h o s e q u e s t i o n s . In p a r t i c u l a r we w i l l f o c u s on t h e f o l l o w i n g q u e s t i o n s : 1. Why does an e n t e r p r i s e r e q u i r e a d a t a d i c t i o n a r y ? 2 . What a r e r e a s o n s f o r n o t i m p l e m e n t i n g a d a t a d i c t i o n a r y ? 3. What a r e some o f t h e c r i t e r i a one s h o u l d c o n s i d e r when c h o o s i n g a d a t a d i c t i o n a r y ? 4. What f a c t o r s s h o u l d be c o n s i d e r e d when i m p l e m e n t i n g a d a t a d i c t i o n a r y ? 94 5.1 The Need F o r A D a t a D i e t i o n a r y In a n s w e r i n g t h e q u e s t i o n an o r g a n i z a t i o n may have c o n -c e r n i n g i t s need f o r a d a t a d i c t i o n a r y , we w i l l f o c u s on t h r e e n eeds t h a t o r g a n i z a t i o n s have i n t h e p r o p e r a l l o c a t i o n of r e -s o u r c e s i n d a t a p r o c e s s i n g . 2 6 F i r s t , t h e r e i s a need t o c o n -t r o l t h e use of d a t a w h i c h i s s h a r e d t o e n s u r e t h a t i t i s c o r -r e c t , and t h a t d a t a i s a v a i l a b l e f o r s y s t e m s w h i c h i d e n t i f y new u s e s o f d a t a s h a r i n g . S e c o n d , t h e r e i s a need w i t h i n d a t a p r o c e s s i n g o r g a n i z a -t i o n s t o a d o p t a f o r m a l m e t h o d o l o g y f o r s y s t e m s d e v e l o p m e n t t o a l l o w f o r d e v e l o p m e n t o f complex s y s t e m s w i t h i n a s m a l l t i m e p e r i o d . A p p l i c a t i o n s d e v e l o p e d a r e no l o n g e r t h e s i m p l e p a y r o l l or a c c o u n t s r e c e i v a b l e s y s t e m s , but a r e c o n s i d e r a b l y more complex, a d d r e s s i n g t h e e n t i r e needs o f a f u n c t i o n a l a r e a . As s y s t e m s become more complex, t h e t i m e n e c e s s a r y t o d e v e l o p them becomes l o n g e r . T h i s i s e s p e c i a l l y t r u e f o r s y s -tems w h i c h use o n - l i n e d a t a e n t r y i n r e a l t i m e o r u t i l i z e a d a t a b a s e management s y s t e m . A d v a n c e s i n h a r d w a r e and t u r n o v e r i n s t a f f r e q u i r e t h e s y s t e m payback t o be r e l a t i v e l y s h o r t . S ystems were once e v a l u a t e d on a c o s t b e n e f i t p e r i o d of f i v e y e a r s . Today t h e c o s t of h a r d w a r e i s d e c r e a s i n g so q u i c k l y , and t e c h n o l o g i c a l advancements o b s o l e t e a s y s t e m i n s u c h a 2 6 B r i t i s h Computer S o c i e t y , p. 8; C a n n i n g , p. Adam, "Data D i c t i o n a r i e s : F o r T h a t M a t u r e Management, 17, No. 10 ( O c t . 1979), 46. 4; R o b e r t G. Look," D a t a 95 s m a l l time p e r i o d , t h a t paybacks a r e now c a l c u l a t e d on a b a s i s of one or two y e a r s . T h i r d , t h e r e i s a need t o c o n t r o l the system development p r o c e s s t o ensure an o p t i m a l a l l o c a t i o n of fu n d s . Because of the l a r g e o u t l a y f o r computer r e s o u r c e s (such as hardware) and the l a r g e e x p e n d i t u r e s f o r maintenance of c u r r e n t systems, a s m a l l budget i s a v a i l a b l e f o r the development of new systems. E v o l u t i o n Of Data Use T r a d i t i o n a l l y , b e f o r e systems were automated, u s e r s deve-l o p e d m e t h o d o l o g i e s t o handle day-to-day b u s i n e s s problems. 2 7 These me t h o d o l o g i e s were l o c a l i n natu r e u t i l i z i n g i n f o r m a -t i o n t h a t the user i d e n t i f i e d as n e c e s s a r y t o do the t a s k . The user prepared, the r e p o r t s and data f i l e s needed t o main-t a i n t h e s e systems. When data was sha r e d , i t was by means of a v e r b a l or w r i t t e n communication which i d e n t i f i e d t o b o t h i n d i v i d u a l s where the da t a came from and where i t went t o . Depending on the n a t u r e of the d a t a , c o r r e c t n e s s was e i t h e r assumed or p r o c e d u r e s were s e t up t o ensure t h a t c o r r e c t n e s s c o u l d be manually v e r i f i e d . W i th the advent of e a r l y computer systems, t h i s l o c a l 2 7 R i c h a r d L. N o l a n , "Computer Data Bases: The F u t u r e I s Now," Ha r v a r d B u s i n e s s Review, 51, No. 5 (1973), 104-5. 96 d e v e l o p m e n t and use of d a t a c o n t i n u e d . D a t a was h e l d i n l o c a l f i l e s f o r a s i n g l e a p p l i c a t i o n and d a t a s h a r i n g was r a r e . When d a t a was s h a r e d , s u c h as a c c o u n t i n g d a t a , t h a t d a t a was l i k e l y m a n u a l l y summarized on a r e p o r t . The a v a i l a b i l i t y o f d a t a , among o t h e r f a c t o r s , soon d i c t a t e d t h a t more and more d a t a be p a s s e d , and a need was i d e n t i f i e d f o r computer s y s t e m s w h i c h would a u t o m a t i c a l l y summarize and p a s s t h e d a t a . T h i s s h a r i n g of d a t a ( e . g . a b i l l i n g s y s t e m p a s s i n g a c -c o u n t s r e c e i v a b l e i n f o r m a t i o n t o an a c c o u n t s r e c e i v a b l e p a c k a g e ) , was done by means of i n t e r m e d i a t e t r a n s a c t i o n f i l e s . T h i s m i m i c k e d t h e e a r l i e r s h a r i n g of d a t a between two u s e r s where a v e r b a l o r w r i t t e n c o m m u n i c a t i o n was p a s s e d from one t o t h e o t h e r . Systems grew more complex ( e . g . m u l t i p l e s o u r c e s of d a t a i n p u t , many sy s t e m s s h a r i n g i n f o r m a t i o n ) , and t h e c o n -t r o l of m u l t i p l e d a t a f i l e s became i n c r e a s i n g l y u n w i e l d y . D a t a b a s e management s y s t e m s e l i m i n a t e d much of t h e d u p l i -c a t i o n of d a t a , i n p a r t i c u l a r m u l t i p l e t r a n s a c t i o n f i l e s . However, s i n c e e a c h u s e r had been a c c u s t o m e d t o a u n i q u e view of d a t a , t h e use of a d a t a b a s e management s y s t e m i d e n t i f i e d t h e need f o r u s e r s t o a g r e e on s t a n d a r d s f o r d a t a d e f i n i t i o n , a c c e s i b l i t y , and s t a n d a r d e d i t c r i t e r i a . U s e r s a l s o became aware of t h e i n t r i n s i c v a l u e of d a t a i n t h o s e i n s t a n c e s when d a t a was n o t a v a i l a b l e from a n o t h e r s y s -tem. One had o n l y t o speak t o t h e c o n t r o l l e r who, when t r y i n g t o do h i s month end, r e a l i z e d t h a t t h e a c c o u n t s p a y a b l e , s y s t e m 9 7 had n ot y e t been run o r t h a t t h e s y s t e m had r u n w i t h e r r o r s t o r e a l i z e t h e v a l u e o f d a t a . E l a b o r a t e backup and r e c o v e r y r o u -t i n e s became n e c e s s a r y a s d a t a was r e q u i r e d n o t o n l y f o r t h e p a r t i c u l a r f u n c t i o n a l a r e a but i n o t h e r a r e a s as w e l l . I t was soon r e a l i z e d t h a t d a t a was no l o n g e r t h e p o s s e s s i o n of any one u s e r , but was a c o r p o r a t e r e s o u r c e t o be s h a r e d by a l l . In t h e c r e a t i o n of d a t a b a s e s , u s e r s were f o r c e d t o make c o n -c e s s i o n s i n d a t a d e s c r i p t i o n and s t o r a g e f o r m a t so t h a t o v e r a l l o b j e c t i v e s c o n c e r n i n g e a s e of use and a c c e s s i b i l i t y were met. The C o r p o r a t e D a t a R e s o u r c e In managing t h i s c o r p o r a t e r e s o u r c e , and m a i n t a i n i n g s t a n d a r d d e f i n i t i o n s a g r e e d t o by u s e r s , a new p o s i t i o n o r f u n c t i o n was c r e a t e d . The d a t a b a s e a d m i n i s t r a t o r (DBA) was pu t i n c h a r g e of c a p t u r i n g and c o n t r o l l i n g t h e d e f i n i t i o n of d a t a . As t h e DBA had o n l y a p a s s i n g i n t e r e s t i n t h e d a t a i t -s e l f , t h i s f u n c t i o n was p e r f e c t l y p l a c e d f o r m e d i a t i n g t h e r e q u i r e m e n t s of u s e r s and d i c t a t i n g t h e d e f i n i t i o n of t h e d a -t a b a s e . The DBA f u n c t i o n p r o v i d e d t h e u s e r w i t h a f e e d b a c k mechanism t o e n s u r e t h a t o p t i m a l use of d a t a was e n f o r c e d and t h a t s t a n d a r d s were a p p r o p r i a t e . In p e r f o r m i n g t h i s t a s k , t h e DBA r e q u i r e d two s o f t w a r e s y s t e m s . The f i r s t was t h e d a t a b a s e management s y s t e m (DBMS) w h i c h would s t o r e t h e d a t a c o n -t r o l l e d . The s e c o n d was a s y s t e m w h i c h would a l l o w t h e DBA t o 98 s t o r e and c e n t r a l l y c o n t r o l t h e s t a n d a r d s f o r t h e d a t a i t e m s i d e n t i f i e d . T h i s s y s t e m we have c a l l e d t h e " d a t a d i c t i o n a r y " . The d a t a d i c t i o n a r y s y s t e m was n o t n e c e s s a r i l y a u t o m a t e d howe-v e r i t c o n t a i n e d b a s i c e l e m e n t s o f d a t a d e s c r i p t i o n . S y s t e m Development M e t h o d o l o g i e s System d e v e l o p m e n t m e t h o d o l o g i e s c l o s e l y p a r a l l e l t h e d e v e l o p m e n t of i n f o r m a t i o n s y s t e m s . The e a r l i e s t i n f o r m a t i o n s y s t e m s d e v e l o p e d were d a t a d r i v e n and u s u a l l y i n v o l v e d a s i n g l e a n a l y s t - p r o g r a m m e r i n t h e i r d e v e l o p m e n t . The methodo-l o g y t h a t t h i s i n d i v i d u a l u s e d i n c l u d e d t h e i n i t i a l i d e n t i f i -c a t i o n of r e p o r t s t h a t a u s e r wanted, s u c h as i n v o i c e s o r c u s -tomer s t a t e m e n t s . F o l l o w i n g t h i s was t h e i d e n t i f i c a t i o n of d a t a n e c e s s a r y t o p r o d u c e t h o s e r e p o r t s and t h e s p e c i f i c a t i o n of f i l e s t o be u s e d . Once t h e o u t p u t had been d e f i n e d and i t s s t o r a g e was i d e n t i f i e d , t h e a n a l y s t u s u a l l y i d e n t i f i e d t h e s o u r c e documents o r d a t a i n p u t n e c e s s a r y t o l o a d t h e f i l e s . Once a l l t h e d a t a i d e n t i f i c a t i o n had been done, t h e a n a -l y s t was r e a d y t o f l o w c h a r t t h e v a l i d a t i o n , and u p d a t e , ex-t r a c t , and r e p o r t programs t h a t were n e c e s s a r y t o c o m p l e t e t h e s y s t e m . A l t h o u g h t h i s m e t h o d o l o g y may not have been f o r m a l l y documented, n e v e r t h e l e s s , i t was t h e m e t h o d o l o g y u s e d i n t u i t i -v e l y by t h e a n a l y s t . I n t e r m e d i a t e f i l e s and r e p o r t s were i d e n t i f i e d a f t e r t h e f a c t , and a s programming t h e s y s t e m c o n -t i n u e d . 99 T h i s m e t h o d o l o g y , w h i c h i s s t i l l u s e d , i s p r o n e t o a number of s e r i o u s p r o b l e m s i n c l u d i n g t h e i n a b i l i t y of t h e u s e r t o r e v i e w and a c c e p t t h e d e s i g n b e f o r e t h e programming has been c o m p l e t e d . P r o b l e m s w i t h t h i s d e s i g n m e t h o d o l o g y become p a r t i c u l a r l y a c u t e when t h e o u t p u t d a t a must s e r v e s e v e r a l u s e r s i n d i f f e r e n t f o r m a t s , and when t h e s y s t e m i s s u f f i c i e n t -l y l a r g e and complex, a s i s t h e c a s e when t h e number of d a t a e l e m e n t s becomes extreme and t h e f u n c t i o n s t h a t t h e s y s t e m must p e r f o r m a r e complex and i n t e r r e l a t e d . The m e t h o d o l o g y i s a l s o s t r a i n e d when a d a t a b a s e management s y s t e m i s u s e d t o s t o r e d a t a . In t h e d e s i g n o f t h e d a t a b a s e s t o r a g e f o r m a t , t h e o r g a n i z a t i o n of d a t a must be o p t i m i z e d , and one o r more of t h e f u n c t i o n s w h i c h use t h e d a t a base may r e q u i r e a s p e c i f i c f o r -mat, c r e a t i n g l e s s t h a n o p t i m a l d e s i g n s f o r o t h e r f u n c t i o n s . In making t h e s e d e c i s i o n s t h e d e t a i l e d a n a l y s i s o f a l t e r n a t e d a t a s t o r a g e s t r a t e g i e s i s n e c e s s a r y . F i n a l l y , t h e model s u g g e s t s t h a t where complex d a t a o r p r o c e s s i n g s y s t e m s a r e d e v e l o p e d , l a r g e r g r o u p s o f p e o p l e w i l l be i n v o l v e d i n t h e d e s i g n . C o m m u n i c a t i o n between t h e s e g r o u p s o f programmers and a n a l y s t s i s c r i t i c a l b e c a u s e of t h e i n t e r -r e l a t i o n of t h e t a s k . T h e r e f o r e , t h e r e w i l l not o n l y be com-m u n i c a t i o n p r o b l e m s between a n a l y s t and u s e r , but communica-t i o n between a n a l y s t s w i t h i n t h e p r o j e c t w i l l r e q u i r e a common bas e of d e f i n i t i o n and an e a s y a c c e s s i b l e s t o r e of i n f o r m a -t i o n . As s y s t e m s have become more complex, t h e m e t h o d o l o g i e s 100 u s e d t o d e s i g n and implement t h o s e s y s t e m s have a l s o become more r e f i n e d . Many modern m e t h o d o l o g i e s e m p h a s i z e two c o n -c e p t s . The f i r s t i s a f u n c t i o n a l a n a l y s i s where e v e n t s and f u n c t i o n s , of. e a c h u s e r a r e a a r e i d e n t i f i e d and. documented. T h i s p r o c e e d s i n a t o p down manner where e a c h i n d i v i d u a l f u n c -t i o n i s decomposed u n t i l i t can be u n d e r s t o o d , u s u a l l y i n terms o f s i m p l e a c t i o n s . U s e r i n v o l v e m e n t i n t h e f u n c t i o n a l a n a l y -s i s e n s u r e s t h a t t h e s y s t e m w i l l model t h e u s e r ' s a c t i o n s . The s e c o n d c o n c e p t i s t h a t o f model b u i l d i n g . T h i s i n v o l v e s t h e i d e n t i f i c a t i o n o f d a t a e n t i t i e s and t h e r e l a t i o n s h i p s b e t -ween d a t a e n t i t i e s u s e d t o p e r f o r m e a c h f u n c t i o n . In model b u i l d i n g , t h e a n a l y s t c a n r e v i e w e a c h d a t a model and e n s u r e t h a t i t i s c o m p l e t e and p r o v i d e s enough i n f o r m a t i o n t o s u p p o r t t h e f u n c t i o n . A t t h e end o f t h i s e x e r c i s e t h e a n a l y s t i s a b l e t o c o m p l e t e t h e c o n c e p t u a l d e s i g n o f t h e s y s t e m ; t h e f u n c t i o n s and d a t a models a r e d e s c r i b e d i n u s e r terms and a r e e a s i l y r e v i e w e d by t h e u s e r . T h i s d o c u m e n t a t i o n of s y s t e m s d e v e l o p -ment f u n c t i o n s and d a t a models becomes u n w i e l d y i f i t i s done m a n u a l l y . What i s needed i s a t o o l w h i c h can r e c o r d and a n a -l y z e u s e r r e q u i r e m e n t s , and d e c i s i o n s made i n t r a n s l a t i n g t h e u s e r d e s i g n i n t o an i m p l e m e n t a t i o n d e s i g n . F i g u r e 5 i s an i l l u s t r a t i o n of t h e d i f f e r e n t i n f o r m a t i o n w h i c h must be c o l l e c t e d by an a n a l y s t d u r i n g h i s u s e r d e s i g n ( l a b e l e d C o n c e p t u a l V i e w ) , and t h e i n f o r m a t i o n n e c e s s a r y t o 101 ABOUT TYPES OF DATA ABOUT THE USE OF DATA DESIGN REQUIREMENTS DESIGN DECISIONS ENTITIES RELATIONSHIPS ATTRIBUTES ACCESS "REQUIREMENTS MAPPING RECORDS DATA ITEMS DATA ITEM GROUPS SETS AREAS FILES DEVICES DATA BASES SCHEMAS, ETC. ACCESS 'REQUIREMENTS EVENTS FUNCTIONS DESIGN PROCESS SYSTEMS PROGRAMS TRANSACTIONS MODULES COMPUTER PROCESSES Data For A n a l y s i s -F i g u r e 5 - S t o r e d by the Data D i c t i o n a r y 102 i n s t a l l t h e a u t o m a t e d s y s t e m ( l a b e l e d I m p l e m e n t a t i o n V i e w ) . 2 8 In t h e c o n c e p t u a l v i e w , t h e d a t a t y p e s i d e n t i f i e d i n c l u d e e n t i t i e s , r e l a t i o n s h i p s , and a t t r i b u t e s . T h e s e must be t r a n s -l a t e d i n t o an i m p l e m e n t a t i o n v i e w w h i c h i n c l u d e s d a t a t y p e s s u c h as d a t a e l e m e n t s , r e c o r d s , f i l e s , d a t a b a s e s , p r o c e s s e s , t r a n s a c t i o n s , modules, p r o g r a m s , and s y s t e m s . U s i n g a d a t a d i c t i o n a r y , an a n a l y s t c a n document e a c h o f t h e s e e n t i t i e s and f u n c t i o n s and p r o d u c e r e p o r t s f o r r e v i e w . U s i n g c r o s s - r e f e r e n c e s , t h e a n a l y s t can d e t e r m i n e t h e impact of a d e s i g n change and e n s u r e c o m p l e t e n e s s o f d o c u m e n t a t i o n . The d a t a d i c t i o n a r y p r o v i d e s a method o f m o n i t o r i n g d e v e l o p -ment and documents t h e c o m p l e t e d s y s t e m . Managing Change The d a t a d i c t i o n a r y c a n a l s o a s s i s t management i n c o n -t r o l l i n g c h a n g e s w h i c h o c c u r i n an i n f o r m a t i o n s y s t e m . 2 9 These c h a n g e s can be due t o t h r e e r e a s o n s . F i r s t , n o rmal de-v e l o p m e n t and g r o w t h of a s y s t e m may c a u s e a c h a n g e . A s y s t e m i s n o r m a l l y not c o m p l e t e l y i m p l e m e n t e d a t one t i m e . A p h a s e d a p p r o a c h i s o f t e n u s e d , where t h e most c r i t i c a l f u n c t i o n s a r e a d d r e s s e d f i r s t , f o l l o w e d by o t h e r f u n c t i o n s as n e c e s s a r y . As 2 8 B r i t i s h Computer S o c i e t y , p. 5. 2 9 I b i d . , p. 8. 1 03 new p h a s e s a r e a u t o m a t e d , a d d i t i o n a l i n f o r m a t i o n may be c a p -t u r e d w h i c h w i l l r e q u i r e t h e m o d i f i c a t i o n o f d a t a s t o r a g e , and p r o g r a m s . S e c o n d , an e n t e r p r i s e i t s e l f may change due t o r e o r g a n i -z a t i o n , merger, o r a change i n management. Government may m o d i f y r e g u l a t i o n s w h i c h d i c t a t e t h e i n f o r m a t i o n t o be s t o r e d and r e p o r t e d , o r t h e e n t e r p r i s e may change i t s market r e -q u i r i n g t h e c a p t u r e and s t o r a g e of new i n f o r m a t i o n . F i n a l l y , change may o c c u r due t o t h e a c q u i s i t i o n of new computer hardware o r s y s t e m s s o f t w a r e . As hardware becomes f a s t e r and l e s s e x p e n s i v e , and more p o w e r f u l s y s t e m s s o f t w a r e i s a v a i l a b l e , a n d / o r s u p p o r t f o r o l d s y s t e m s i s withdrawn by v e n d o r s , new a p p l i c a t i o n s s o f t w a r e may need t o be im p l e m e n t e d . To c o n t r o l t h i s change a t o o l i s n e c e s s a r y w h i c h w i l l a l l o w t h e a n a l y s t t o q u i c k l y and e a s i l y i d e n t i f y t h e l o c a t i o n and e x t e n t of t h e change, and t h e e f f o r t n e c e s s a r y t o make t h e c h a n g e . The d a t a d i c t i o n a r y p r o v i d e s a b a s e l i n e w h i c h r e c o r d s t h e p r e s e n t and p a s t s y s t e m s d e f i n i t i o n s and g i v e s some i n d i -c a t i o n o f t h e d i r e c t i o n i n w h i c h t h e s y s t e m i s moving. A d a t a d i c t i o n a r y can p r o v i d e i n f o r m a t i o n n e c e s s a r y t o do a d e t a i l e d a n a l y s i s o f t h e c h a n g e . I t can model a p r o p o s e d s y s t e m and be u s e d t o i d e n t i f y m i s s i n g i n f o r m a t i o n . I t c a n i d e n t i f y s y s t e m i n t e r f a c e s and c a n be u s e d t o r e v i e w t h e s y s t e m i n t h e o v e r a l l o r g a n i z a t i o n a l s t r u c t u r e . The d a t a d i c t i o n a r y s y s t e m can a l s o a s s i s t i n c o s t i n g t h e change by i d e n t i f y i n g t h e impact of mo-1 04 e d i f i c a t i o n s , t h e sequence of m o d i f i c a t i o n s , and t h e number of i n t e r f a c e s w h i c h might r e q u i r e c h a n g e . D a t a P r o c e s s i n g E n v i r o n m e n t In i d e n t i f y i n g t h e need f o r a d a t a d i c t i o n a r y i n an o r -g a n i z a t i o n , o p p o n e n t s may a r g u e t h a t t h e d a t a p r o c e s s i n g en-v i r o n m e n t w h i c h e x i s t s may n o t be a b l e t o s u p p o r t a d a t a d i c -t i o n a r y , o r may not even r e q u i r e one. A d a t a d i c t i o n a r y c a n s u p p o r t t h e a c t i v i t i e s of a v a r i e t y of d a t a p r o c e s s i n g e n -v i r o n m e n t s : 1. The c o n v e n t i o n a l e n v i r o n m e n t w h i c h u s e s s e q u e n t i a l , o r i n d e x s e q u e n t i a l , d a t a f i l e s . 2. An e n v i r o n m e n t w h i c h i s c o n v e r t i n g t o a d a t a b a s e manage-ment s y s t e m . 3. One t h a t has a s i n g l e d a t a b a s e management s y s t e m . 4. A complex e n v i r o n m e n t u t i l i z i n g one o r more d a t a b a s e management s y s t e m s , one o r more c e n t r a l p r o c e s s i n g u n i t s , a d i s t r i b u t e d d a t a b a s e , o r d i s t r i b u t e d p r o c e s -s i n g . In a c o n v e n t i o n a l e n v i r o n m e n t ( s e e F i g u r e 6 ) , a p p l i c a t i o n p r o grams a r e d e s i g n e d t o a c c e s s a d i s t i n c t s e t o f f i l e s . In t h i s e n v i r o n m e n t t h e d a t a d i c t i o n a r y i s a f r e e - s t a n d i n g s e t of f i l e s . The u t i l i t i e s w h i c h s u p p o r t i t run i n b a t c h mode and e x t r a c t d a t a t o s u p p o r t d a t a v a l i d a t i o n and b a s i c d a t a 105 F i g u r e 6 D a t a D i c t i o n a r y i n a C o n v e n t i o n a l E n v i r o n m e n t 106 d e f i n i t i o n s w h i c h a r e p l a c e d i n t o s y s t e m l i b r a r i e s . A m a j o r i -t y o f t h e d a t a d i c t i o n a r i e s i n use a r e of t h i s t y p e . They p r o v i d e an i m p l e m e n t a t i o n view of d a t a t h r o u g h f i l e d e f i n i -t i o n s , and a j o b l i b r a r y t h r o u g h f i l e and t a s k r e l a t i o n s h i p s . The s y s t e m c a n a l s o a s s i s t i n p r e p a r i n g d e v i c e l a y o u t s u s i n g c r o s s - r e f e r e n c e s between d a t a f i l e s and t h e i r v o l u m e s . D u r i n g a c o n v e r s i o n t o a d a t a b a s e management s y s t e m , t h e d a t a d i c t i o n a r y can p e r f o r m two t a s k s ( i d e n t i f i e d i n F i g u r e 7 ) . In t h e f i r s t t a s k , d e f i n i t i o n , t h e d a t a d i c t i o n a r y c a n a s s i s t i n l o c a t i n g t h e n e c e s s a r y d a t a e l e m e n t s and g r o u p s . D a t a d i c t i o n a r y o u t p u t c a n t h e n e i t h e r a u t o m a t i c a l l y g e n e r a t e t h e schema f o r t h e d a t a b a s e management s y s t e m o r o u t p u t s u f f i -c i e n t i n f o r m a t i o n so t h a t t h e schema c a n be m a n u a l l y p r e p a r e d . I f a d a t a b a s e management s y s t e m has a l r e a d y been d e s i g n e d , t h e n t h e r e s h o u l d be an i n t e r f a c e between t h e d a t a b a s e manage-ment s y s t e m and t h e d a t a d i c t i o n a r y t o a l l o w l o a d i n g o f d a t a d i c t i o n a r y d e f i n i t i o n s . A u t i l i t y s h o u l d e x i s t t o a l l o w app-l i c a t i o n p rograms t o be s e a r c h e d f o r program d a t a d e f i n i t i o n s n o t c o n t a i n e d i n t h e d a t a d i c t i o n a r y or t h e d a t a b a s e manage-ment s y s t e m . The o u t p u t of s u c h an a n a l y s i s would be a d i s -c r e p a n c y r e p o r t which c o u l d be u s e d i n t h e s e c o n d p h a s e . The s e c o n d c o n v e r s i o n t a s k i s t o m o d i f y e x i s t i n g programs t o i n t e r f a c e w i t h t h e d a t a b a s e management s y s t e m . T h i s i s done u s i n g t h e d i s c r e p a n c y r e p o r t i d e n t i f i e d i n t h e d e f i n i t i o n s t e p . Changes a r e m a n u a l l y o r a u t o m a t i c a l l y made t o t h e p r o -gram d a t a d e f i n i t i o n t o p r o d u c e a new s o u r c e p r o g r a m w h i c h i s PROGRAM SOURCE DDS ANALYSIS/ EDIT 1 f REPORT ON DISCREPAN CIES MANUAL OR • AUTOMATED ' REEDIT NEW SOURCE D e f i n i t i o n Update DBMS INSTALLAT-ION F i g u r e 7 D a t a D i c t i o n a r y D u r i n g a DBMS I n s t a l l a t i o n 108 c o n s i s t e n t w i t h t h e r e q u i r e m e n t s of t h e d a t a b a s e management s y s t e m . U s i n g t h e d a t a d i c t i o n a r y t o document t h e p r o c e s s e s t h a t o c c u r w i t h i n a prog r a m , i t c a n i d e n t i f y t h e n e c e s s a r y c a l l s t o r e t r i e v e d a t a from t h e DBMS. In s u p p o r t i n g t h e s i n g l e d a t a b a s e management sy s t e m , t h e d a t a d i c t i o n a r y c a n e i t h e r be a f r e e - s t a n d i n g s o f t w a r e p a c -kage, w h i c h does n ot r e l y on a d a t a b a s e management s y s t e m f o r i t s o p e r a t i o n , or i t c a n be imp l e m e n t e d u s i n g a d a t a b a s e mana-gement s y s t e m . When implemented a s p a r t of a d a t a b a s e management s y s t e m , t h e d a t a d i c t i o n a r y c a n e i t h e r be implemented a s a s e p a r a t e a p p l i c a t i o n o r i t c a n be i n t e g r a t e d . An i n t e g r a t e d DBMS-data d i c t i o n a r y would use d a t a d i c t i o n a r y i n f o r m a t i o n a s t h e d i r e c -t o r y t o t h e DBMS. A l t h o u g h t h i s i m p l e m e n t a t i o n i s more comp-l e x , i t a l l o w s t h e u s e r t o . a c c e s s a s i n g l e s o f t w a r e s y s t e m i n o r d e r t o i d e n t i f y and e x t r a c t t h e i n f o r m a t i o n t h a t he r e -q u i r e s . 3 0 In a complex e n v i r o n m e n t t h e o r g a n i z a t i o n may have one o r more c e n t r a l p r o c e s s i n g u n i t s l o c a t e d c e n t r a l l y , o r d i s t r i -b u t e d . D a t a b a s e management s y s t e m s and s e q u e n t i a l and i n d e x e d f i l e s a r e u s e d , and a p p l i c a t i o n s y s t e m s e x t r a c t i n f o r m a t i o n f r o m t h e d a t a b a s e s , o r c o n v e n t i o n a l f i l e s a c c e s s i n g one o r more CPUs. 3 0 Sharman and W i n t e r b o t t o m , p.187. 109 In t h i s e n v i r o n m e n t , t h e t i m e s p e n t by d a t a p r o c e s s i n g s t a f f m a i n t a i n i n g o p e r a t i o n a l c o n t r o l o v e r d a t a and p r o c e s s e s i s a m a j o r t a s k . New s y s t e m s may have t o i n t e r f a c e w i t h a number o f d i f f e r e n t d a t a b a s e management s y s t e m s , e a c h w i t h i t s own p r o t o c o l s . I n d e p e n d e n c e from p h y s i c a l s t o r a g e , w h i c h i s one of t h e aims of t h e d a t a b a s e management s y s t e m , once a g a i n becomes a p r o b l e m . Programmers and a n a l y s t s a r e once a g a i n f o r c e d t o c o n s i d e r t h e s t o r a g e m e t h o d o l o g y and d a t a f i l e d e s i g n i n p r e p a r i n g s y s t e m d e f i n i t i o n s . A d a t a d i c t i o n a r y c a n h e l p by p r o v i d i n g an i n t e r f a c e between s y s t e m s and m u l t i p l e s t o r a g e s t r u c t u r e s . In a d d i t i o n , t h e d a t a b a s e c a n r e c e i v e and p r o c e s s d a t a r e t r i e v a l r e q u e s t s even t h o u g h t h e y may r e s i d e on d i f f e r e n t m a c h i n e s and i n d i f f e r e n t d a t a b a s e s . 3 1 The f a c t t h a t d a t a may be d i s t r i b u t e d o v e r more t h a n one d a t a b a s e o r machine, r a i s e s t h e p r o b l e m of h a v i n g a c e n t r a l o r d i s t r i b u t e d d a t a d i c t i o n a r y . 3 2 In a c e n t r a l d a t a d i c t i o n a r y , a l l d e f i n i t i o n s a r e h e l d c e n t r a l l y and e v e r y one must a c c e s s t h e same d a t a d i c t i o n a r y . A l t h o u g h t h i s i s t h e t h e most c o n -s i s t e n t d e s i g n , t h e r e w i l l be r e d u n d a n t d a t a c o m m u n i c a t i o n s . The o t h e r extreme i s t o have d e f i n i t i o n s d i s t r i b u t e d t o e a c h 3 1 F a b i o A. S c r e i b e r and G. M a r t e l l a , " C r e a t i n g a C o n c e p t u a l Model o f a D a t a D i c t i o n a r y f o r D i s t r i b u t e d D a t a B a s e s , " D a t a  Base, 11, No. 1 ( 1 9 7 9 ) , 12-8. 3 2 R. A. D a v e n p o r t , " D e s i g n of D i s t r i b u t e d D a t a Base S y s t e m s , " Computer J o u r n a l , 24, No. 1 ( 1 9 7 8 ) , 31-41; G e r a l d L. Power, " D e v e l o p i n g y o u r D i s t r i b u t e d D a t a Base," C o m p u t e r w o r l d , 15 ( J a n . 12, 1981), In D e p t h 33-8. 1 10 o f t h e remote p r o c e s s i n g c e n t r e s . In t h i s c a s e no d a t a com-m u n i c a t i o n s a r e n e c e s s a r y e x c e p t t o e x t r a c t and u p d a t e t h e d a t a d i c t i o n a r i e s i n e a c h of t h e l o c a t i o n s . I f d a t a i s l o -c a t e d i n a remote l o c a t i o n , t h e d a t a d i c t i o n a r y w i l l e x e c u t e t h e p r o p e r i n s t r u c t i o n s t o r e t r i e v e t h a t d a t a . The o p t i m a l d e s i g n may be a h y b r i d o f t h e s e two: some d e f i n i t i o n s h e l d o n l y a t t h e l o c a l d a t a d i c t i o n a r y s i t e and some d e f i n i t i o n s h e l d c e n t r a l l y . In d e c i d i n g t h e l o c a t i o n of i n f o r m a t i o n , a s t a t i s t i c a l a n a l y s i s o f r e t r i e v a l r e q u e s t s would be n e c e s s a r y . A d a t a d i c t i o n a r y c an a s s i s t i n t h i s t a s k . One o f t h e a d v a n t a g e s o f u s i n g a d a t a d i c t i o n a r y i n t h i s e n v i r o n m e n t i s t h e s t a n d a r d i n t e r f a c e f o r m a t between a p p l i c a -t i o n p r o g r a m s and t h e d a t a r e s o u r c e . The d a t a d i c t i o n a r y c a n s t o r e i n d i v i d u a l r o u t i n e s f o r i n t e r f a c i n g t o d a t a b a s e manage-ment s y s t e m s or c o n v e n t i o n a l f i l e s . In i n s t a l l i n g a d a t a d i c t i o n a r y , o t h e r arguments a r e o f t e n r a i s e d . One i s t h a t a d a t a d i c t i o n a r y i s d i f f i c u l t t o j u s t i f y i n terms of e x p e n d i t u r e b e c a u s e o f t h e d i f f i c u l t y i n i d e n t i f y i n g t a n g i b l e b e n e f i t s t h a t a c c r u e o u t o f i t . We have shown t h a t t h e r e a r e u t i l i t i e s w h i c h a r e a v a i l a b l e w i t h modern d a t a d i c t i o n a r i e s t o r e d u c e t h e ammount of programmer t i m e n e c e s s a r y t o c o m p l e t e p r o g r a m s ( t h r o u g h d a t a d i v i s i o n g e n e r a -t i o n , v a l i d a t i o n r o u t i n e g e n e r a t i o n ) and d a t a base d e f i n i -t i o n s . A l t h o u g h t h e c a l c u l a t i o n o f s u c h t i m e s a v e d would r e -q u i r e some e f f o r t , i t i s a t a n g i b l e b e n i f i t . 111 A n o t h e r i s t h a t t h e l e v e l o f e f f o r t n e c e s s a r y t o g a t h e r i n f o r m a t i o n f o r t h e d a t a d i c t i o n a r y ; t h a t i s , t o i d e n t i f y , g a t h e r , s t a n d a r d i z e and o b t a i n c o n s e n s u s from u s e r s on d a t a d e f i n i t i o n s , p r o c e s s d e f i n i t i o n s , and c o n c e p t u a l e n t i t y de-f i n i t i o n s , i s a t a s k t h a t consumes a v a s t amount of r e s o u r c e s . T h i s was t r u e f o r u s e r s of d a t a d i c t i o n a r y p a c k a g e s w h i c h d i d no t have u t i l i t i e s t o e x t r a c t d a t a d e f i n i t i o n s from programs or d a t a base d i r e c t o r i e s . I t i s a l s o t r u e when u s e r s a t t e m p t t o l o a d a l l d a t a , p r o c e s s and d a t a i n t e r c h a n g e e n t i t i e s a t one t i m e . As we w i l l d i s c u s s l a t e r , t h e r e a r e o p p o r t u n i t i e s where t h e c o l l e c t i o n and i n p u t of d a t a d i c t i o n a r y d a t a i s b e s t done as t h e b e n e f i t s a r e e a s i l y s e e n . These o p p o r t u n i t i e s a r e f r e -q u e n t l y i n s t a n c e s where t h e d a t a d i c t i o n a r y c an r e d u c e t h e r i s k o f f a i l u r e (as when i n s t a l l i n g a l a r g e a p p l i c a t i o n s y s -tem) b e c a u s e t h e t a s k i s b e t t e r bounded and c o m m u n i c a t i o n among t h e team members can be e n h a n c e d . S t i l l a n o t h e r i s t h a t t h e s t a n d a r d i z a t i o n o f d a t a d e f i n i -t i o n s i s n o t w i t h i n t h e r e a l m o f a c e n t r a l i z e d c o r p o r a t e f u n c -t i o n , b u t t h a t t h e d a t a d e f i n i t i o n s h o u l d r e m a i n t h e p r o p e r t y of t h e u s e r . The u s e r s h o u l d i d e n t i f y t h e name, v a l i d a t i o n s t a n d a r d s , and o t h e r p a r a m e t e r s of t h e d e f i n i t i o n as i t r e -l a t e s t o h i s own e n v i r o n m e n t . The u s e r m i g h t a r g u e t h a t no j u s t i f i c a t i o n can be f o u n d f o r s t a n d a r d i z i n g d e f i n i t i o n s w h i c h a r e l o c a l . T h i s argument i s a l s o p a r t i a l l y t r u e . The e f f o r t of c a p t u r i n g a l l l o c a l l y u s e d d a t a d e f i n i t i o n s s i m p l y t o e x e r -c i s e c o n t r o l i s not what we c o n s i d e r a w i s e use of t h e d a t a 1 1 2 d i c t i o n a r y s y s t e m . S t a n d a r d i z a t i o n i s j u s t i f i e d when t h e s h a r i n g o f d a t a i s e n h a n c e d . I t i s d i f f i c u l t f o r t h e l o c a l u s e r t o a r g u e t h a t t h e r e i s no c h a n c e o f t h e d a t a e v e r b e i n g s h a r e d . I t i s a q u e s t i o n of p r i o r i t i e s . The DBA s h o u l d i n s i s t t h a t i f t h e d a t a d e f i n i t i o n s a r e t o be us e d i n t h e de-v e l o p m e n t of an a p p l i c a t i o n , t h e n t h e d e f i n i t i o n s s h o u l d be e n t e r e d i n t o a d a t a d i c t i o n a r y , o t h e r w i s e t h e e f f o r t c a n n o t be c o s t j u s t i f i e d . The d a t a d i c t i o n a r y i s an o v e r h e a d i t e m . Many s o u r c e s c l a i m t h a t when budget c u t s a r e made t h e d a t a d i c t i o n a r y and t h e d a t a b a s e a d m i n i s t r a t o r f u n c t i o n s w i l l l i k e l y be t h e f i r s t t o f e e l t h e p r e s s u r e . D a t a p r o c e s s i n g r e s o u r c e s w i l l be d i -v e r t e d t o t h o s e s y stems i n w h i c h i t i s e a s y t o show a p o s i t i v e p a y b ack i n terms of s t a f f r e d u c t i o n or t a n g i b l e r e d u c t i o n i n i n v e n t o r y or r e c e i v a b l e s b a l a n c e s . We have seen t h a t d a t a d i c t i o n a r y u t i l i t i e s c a n d e l i v e r b e n e f i t s i n t h e r e d u c t i o n of d e s i g n and programming t i m e , and t h e enhancement of u s e r - a n a -l y s t c o m m u n i c a t i o n . These a r e t a n g i b l e b e n e f i t s , n ot e a s i l y q u a n t i f i e d , and may be o v e r l o o k e d when e v a l u a t i n g e f f e c t s on t h e b o t t o m l i n e . 5.2 S o f t w a r e S e l e c t i o n Once management has made a commitment t o t h e i n s t a l l a t i o n o f a d a t a d i c t i o n a r y , t h e i m p l e m e n t a t i o n p l a n f o r t h e s y s t e m must be p r e p a r e d . Two key q u e t i o n s w h i c h w i l l be a s k e d a r e : 1 1 3 1. S h o u l d t h e d a t a d i c t i o n a r y s y s t e m be d e v e l o p e d i n - h o u s e o r a s h o u l d a c o m m e r c i a l l y a v a i l a b l e package be p u r -c h a s e d ? 2. What t y p e s of f e a t u r e s s h o u l d t h e d a t a d i c t i o n a r y c o n -t a i n ? I n - h o u s e Development In d e c i d i n g whether t o p u r c h a s e a p a c k a g e o r c u s t o m p r o -gram t h e s y s t e m i n t e r n a l l y , t h e a n a l y s i s i s s i m i l a r t o any o t h e r a p p l i c a t i o n s y s t e m d e v e l o p m e n t e v a l u a t i o n . The d e c i s i o n i s g u i d e d by t h e a v a i l a b i l i t y of s o f t w a r e p a c k a g e s w h i c h c o n -t a i n t h e d e s i r e d f e a t u r e s a t a r e a s o n a b l e c o s t . The c o s t o f c o m p u t i n g manpower and t h e c o m p l e x i t y o f even t h e most b a s i c d a t a d i c t i o n a r y , w i t h a l l o f i t s a t t e n d a n t i n t e r f a c e s and u t i -l i t i e s , l e a n t h e d e c i s i o n h e a v i l y i n f a v o u r of p u r c h a s i n g a s o f t w a r e p a c k a g e . I t i s u n l i k e l y , c o n s i d e r i n g t h e number o f good s o f t w a r e p a c k a g e s a v a i l a b l e , t h a t i t would be more c o s t l y t o implement a s t a n d a r d p a c k a g e and add s p e c i a l i z e d i n t e r f a c e s t o f u l f i l l t h e u n i q u e needs of a p a r t i c u l a r e n t e r p r i s e ' s r e -q u i r e m e n t s , r a t h e r t h a n w r i t i n g t h e e n t i r e d a t a d i c t i o n a r y s y s t e m from f i r s t p r i n c i p l e s . 1 1 4 S e l e c t i o n C r i t e r i a I n s e l e c t i n g a s u i t a b l e s o f t w a r e p a c k a g e , a s e t o f c r i -t e r i a i s r e q u i r e d on w h i c h c a n d i d a t e s y s t e m s c a n be r a n k e d . T h i s r a n k i n g can be d i v i d e d i n t o f e a t u r e s w h i c h a r e n e c e s s a r y and t h o s e which a r e d e s i r a b l e . F o r t h e p u r p o s e s o f d i s c u s s i o n we have have b r o k e n e v a l u a t i o n c r i t e r i a i n t o t h r e e c a t e g o r i e s : 1. D i c t i o n a r y c o n t e n t s . 2. D i c t i o n a r y u t i l i t i e s . 3. D i c t i o n a r y e n v i r o n m e n t . D i e t i o n a r y C o n t e n t s The c o n t e n t s of a d a t a d i c t i o n a r y s y s t e m can be b r o k e n down i n t o f o u r c a t e g o r i e s . F i r s t , b a s i c e n t i t y d a t a s u c h as i t s name, d e f i n i t i o n , where and how i t i s u s e d , r e l a t i o n s h i p s t o o t h e r d a t a , l a b e l s , and key word d e s i g n a t o r s . The b a s i c d a t a d i c t i o n a r y s h o u l d a l s o have f a c i l i t i e s t o r e c o r d comments d e a l i n g w i t h t h e e n t i t y d e r i v a t i o n , and t h e i n d i v i d u a l s r e s -p o n s i b l e f o r i t s i n p u t , u p d a t e and u s a g e . The s y s t e m s h o u l d a l s o r e c o r d d a t e s of i n p u t and keep t r a c k of i t s l a s t c h a n g e . S e c o n d , t h e d a t a d i c t i o n a r y s h o u l d r e c o r d t e c h n i c a l i n -f o r m a t i o n . F o r d a t a e n t i t i e s t h i s would i n c l u d e t h e i r l e n g t h , p r e c i s i o n , v a l u e , r a n g e , an d b a c k u p r o u t i n e s . F o r p r o c e s s e n t i t i e s i t would i n c l u d e l a n g u a g e , p r o c e s s o r , s p e c i a l c a l c u -1 1 5 l a t i o n s , r u n t i m e , and r e c o v e r y r o u t i n e s . S i m i l a r a t t r i b u t e s s h o u l d be m a i n t a i n e d f o r equipment e n t i t i e s s u c h as p r o c e s s i n g u n i t s and s t o r a g e d e v i c e s . The t h i r d t y p e of i n f o r m a t i o n s t o r e d by a d a t a d i c t i o n a r y i s r e l a t i o n s h i p i n f o r m a t i o n , i n c l u d i n g l i n k s between l o w e r l e v e l and h i g h l e v e l s t r u c t u r e s . F o r example, t h e r e s h o u l d be a means o f r e l a t i n g d a t a e l e m e n t s t o d a t a f i l e s , o r d a t a e l e -ments t o d a t a b a s e s t r u c t u r e s . T h e r e s h o u l d a l s o be a f a c i l i t y f o r i d e n t i f y i n g s e q u e n c e of e l e m e n t s w i t h i n r e c o r d s and s e -q u e n c e s of r e c o r d s w i t h i n f i l e s . S i m i l a r l y , f o r p r o c e s s i n g e n t i t i e s , t h e r e s h o u l d be r e l a t i o n s h i p s w h i c h i d e n t i f y modules w i t h i n p r o g r a m s and programs w i t h i n s y s t e m s . L i n k s s h o u l d a l s o be m a i n t a i n e d between d a t a e n t i t i e s and p r o c e s s i n g e n t i -t i e s , f o r example, t o r e l a t e d a t a e l e m e n t s t o p r o g r a m s . The f o u r t h c a t a g o r y i s t h e r e a l m of e n t i t i e s s u p p o r t e d by th e d a t a d i c t i o n a r y . Some e n t i t i e s may be s p e c i f i c t o a p a r -t i c u l a r p r o c e s s i n g e n v i r o n m e n t s u c h as t h e a b i l i t y t o s t o r e IMS d a t a s t r u c t u r e s t o s u p p o r t an IMS d a t a b a s e management s y s -tem. In a CODASYL e n v i r o n m e n t , i t would be n e c e s s a r y t o s t o r e schema o r sub-schema i n f o r m a t i o n . The d a t a d i c t i o n a r y s y s t e m s h o u l d r e c o r d i n f o r m a t i o n a b o u t b a s i c d a t a e n t i t i e s s u c h a s e l e m e n t s , f i l e s , r e c o r d s , and b a s i c p r o c e s s i n g e n t i t i e s s u c h as t r a n s a c t i o n s , m o d u l e s , and s y s t e m s . The d a t a d i c t i o n a r y s y s t e m s h o u l d s t o r e i n f o r m a t i o n a b o u t o p e r a t i n g s y s t e m e n t i -t i e s ( r u n c o n t r o l l a n g u a g e ) , t r a n s a c t i o n s , d a t a g r o u p s , r e -p o r t s , documents, and n o n - s t a n d a r d e n t i t i e s w h i c h a r e r e l a t e d 1 1 6 t o t h e c o n c e p t u a l s y s t e m d e f i n i t i o n . DATAMANAGER a l l o w s e n t i t y t y p e s s u c h a s p r o c e s s , s u b - p r o c e s s , d a t a s t o r e , d a t a f l o w , and d a t a s t r u c t u r e w h i c h a s s i s t i n s u p p o r t i n g s t r u c t u r e d a n a l y s i s . D i e t i o n a r y U t i l i t i e s The d a t a d i c t i o n a r y s y s t e m w i l l o n l y b e n e f i t t h e e n t e r -p r i s e i f i t i s s u p p o r t e d by a c o m p r e h e n s i v e s e t o f e a s y - t o - u s e u t i l i t i e s . The b a s i c s e t s h o u l d i n c l u d e d a t a i n p u t u t i l i t i e s , u t i l i t i e s t o p r o d u c e r e p o r t s w h i c h document t h e s t a t e o f t h e d a t a d i c t i o n a r y , and u t i l i t i e s w h i c h s u p p o r t programming t a s k s . I n p u t u t i l i t i e s i n c l u d e p rograms t o l o a d b u l k d a t a i n t o t h e d a t a d i c t i o n a r y , and a i d s f o r e x t r a c t i n g d a t a e n t i t y d e-f i n i t i o n s from p r o g r a m s and e x i s t i n g d a t a b a s e s , o r o n - l i n e d a t a i n p u t t o t h e d a t a d i c t i o n a r y . The d a t a d i c t i o n a r y r e -q u i r e s an e x t e n s i v e v a l i d a t i o n s y s t e m t o e n s u r e t h a t o n l y v a l i d d a t a i s a c c e p t e d . T h e r e s h o u l d be f a c i l i t i e s t o automa-t i c a l l y g e n e r a t e r e l a t i o n s h i p s between d i f f e r e n t e n t i t i e s , i n c l u d i n g r e f e r e n c e s b o t h ways ( e . g . t o i d e n t i f y p r ograms when l o o k i n g a t e l e m e n t e n t i t i e s , and e l e m e n t s when l o o k i n g a t pro g r a m e n t i t i e s ) . O n - l i n e i n p u t s h o u l d be u s e r - f r i e n d l y , a l l o w i n g t h e u s e r t o r e q u e s t h e l p i n c o m p l e t i n g a l l i n p u t . I t s h o u l d be o r g a n i z e d so t h a t b o t h t h e needs o f t h e c a s u a l and c o n f i d e n t u s e r a r e s e r v e d . The d a t a d i c t i o n a r y s h o u l d a l l o w 1 17 more t h a n one s t a t u s o f e n t r y so t h a t i n c o m p l e t e i n p u t c a n be r e c o r d e d . A c o m p r e h e n s i v e b a c k u p / r e s t o r e f a c i l i t y , s u f f i c i e n t f o r t h e l e v e l o f o n - l i n e d a t a e n t r y , i n c l u d i n g t r a n s a c t i o n l o g g i n g , o r c h e c k p o i n t i n g , s h o u l d be s u p p l i e d w i t h t h e o n l i n e i n t e r f a c e . R e p o r t i n g u t i l i t i e s s u p p o r t e d by t h e d a t a d i c t i o n a r y s h o u l d i n c l u d e l i s t s f o r e a c h t y p e of e n t i t y , w i t h t h e a b i l i t y t o s e l e c t t h e o u t p u t b a s e d on keywords o r s p e c i f i c r a n g e s of a t t r i b u t e v a l u e s . S t a n d a r d r e p o r t s s h o u l d a l l o w f o r u s e r e x i t s t h a t m o d i f y s t a n d a r d r e p o r t s f o r u s e r r e q u i r e m e n t s . C r o s s - r e f e r e n c e s s h o u l d be p r o v i d e d . Systems s h o u l d s u p p l y KWIC i n d e x e s on keywords and s h o u l d be a b l e t o c o n s t r u c t s t r u -c t u r e d i a g r a m s o f e n t i t i e s . T h e r e s h o u l d a l s o be a f a c i l i t y t o g e n e r a t e d o c u m e n t a t i o n f o r s y s t e m s b a s e d on a s t a n d a r d l i s t . T h i s would a l l o w t h e u s e r t o i d e n t i f y t h e t y p e s of r e -p o r t s n e c e s s a r y t o document a p r o g r a m or a s y s t e m . In t h i s way many mundane s y s t e m d o c u m e n t a t i o n t a s k s c o u l d be au-toma t e d . Program u t i l i t i e s c a n be b r o k e n down i n t o two t y p e s . The f i r s t and most u s e f u l a r e t h o s e u t i l i t i e s w h i c h a u t o m a t i c a l l y g e n e r a t e p r o g ram code b a s e d on i n f o r m a t i o n c o n t a i n e d i n t h e d a t a d i c t i o n a r y . F o r example, t h e g e n e r a t i o n o f d a t a d i v i -s i o n s i n t o s y s t e m - m a i n t a i n e d c o p y l i b r a r i e s f o r s u b s e q u e n t c o p y i n g i n t o s o u r c e p r o g r a m s . In s p e c i f y i n g t h e d a t a n e c e s -s a r y t o be i n c l u d e d u s i n g t h e d a t a d i c t i o n a r y , one can e n s u r e t h a t t h e d e f i n i t i o n o f t h e co p y l i b r a r y w i l l be c o n s i s t e n t 118 w i t h o t h e r d e f i n i t i o n s of t h e same d a t a . T h i s r e l i e v e s t h e programmer and t h e a n a l y s t from t h e t a s k o f e n s u r i n g t h a t d a t a d e f i n i t i o n s a r e c o n s i s t e n t i n t h e d i f f e r e n t f i l e d e f i n i t i o n s t h a t t h e y may a p p e a r . O t h e r u t i l i t i e s w h i c h g e n e r a t e program c o d e t o v a l i d a t e i n p u t d a t a , c a l l a d a t a b a s e t o r e t r i e v e i n -f o r m a t i o n , o r h a n d l e i n p u t - o u t p u t e r r o r s w i t h s t a n d a r d e r r o r messages would a l s o f a l l under t h i s c a t e g o r y . The s e c o n d t y p e of p r o g r a m u t i l i t y i s one w h i c h i n t e r -f a c e s progams w i t h t h e d a t a d i c t i o n a r y . T h e s e u t i l i t i e s r e a d p r o g r a m d a t a d e f i n i t i o n s and v e r i f y t h a t t h e d e f i n i t i o n s a r e c o n s i s t e n t w i t h i n f o r m a t i o n s t o r e d i n t h e d a t a d i c t i o n a r y . I f no i n f o r m a t i o n i s s t o r e d i n t h e d a t a d i c t i o n a r y , p r o p e r i n p u t t r a n s a c t i o n s a r e g e n e r a t e d t o u p d a t e t h e d a t a d i c t i o n a r y . F o r example, DATAMANAGER has an i n t e r f a c e t o t h e LIBRARIAN program l i b r a r y s y s t e m , w h i c h a l l o w s t h e d a t a d i c t i o n a r y and t h e s o u r c e p r o g ram l i b r a r y t o s y n c h r o n i z e t h e i r c o n t e n t s w i t h o u t c l e r i c a l u p d a t i n g * T h i s e n s u r e s t h a t t h e d a t a d i c t i o n a r y and t h e l i b r a r y management s y s t e m have c o n s i s t e n t v i e w s o f t h e p r o g r a m d a t a d e f i n i t i o n . O t h e r p r o g ram u t i l i t i e s w h i c h can be i m plemented a r e t h e o u t p u t o f j o b c o n t r o l l a n g u a g e f o r s y s t e m s o p e r a t i o n , and t h e g e n e r a t i o n of r o u t i n e s f o r t h e a u t o m a t i c r e c o v e r y / r e s t a r t of s y s t e m s when t h e y f a i l . O t h e r u t i l i t i e s w h i c h s h o u l d be s u p p o r t e d by t h e d a t a d i c t i o n a r y s y s t e m i n c l u d e a q u e r y l a n g u a g e , w h i c h a l l o w s on-119 l i n e q u e r y on an a t t r i b u t e , r e l a t i o n s h i p and e n t i t y , or by keyword. The q u e r y l a n g u a g e s h o u l d be e a s y t o use and s h o u l d a l l o w f o r h a r d copy r e p o r t i n g o f t h e o u t p u t . U t i l i t i e s w h i c h may be s u p p o r t e d by a d a t a d i c t i o n a r y i n c l u d e t h e a b i l i t y t o i n t e r f a c e w i t h one or more d a t a b a s e management s y s t e m s , i n c l u -d i n g p r o d u c t i o n of d a t a b a s e d e f i n i t i o n s u s i n g a l o g i c a l d e s i g n d e f i n e d i n t h e d a t a d i c t i o n a r y s y s t e m , and t h e g e n e r a t i o n of c o n t r o l l a n g u a g e t o a u t o m a t i c a l l y l o a d t h e d a t a b a s e . L i k e w i s e , an i n t e r f a c e w i t h t h e a b i l i t y t o r e a d t h e d a t a b a s e management s y s t e m may a l s o e x i s t , so t h a t d e f i n i t i o n s c o u l d be l o a d e d i n t o t h e d a t a d i c t i o n a r y f r o m t h e d a t a b a s e management s y s t e m d i r e c t o r y . The d a t a d i c t i o n a r y s h o u l d a l s o a l l o w f o r c r o s s - r e f e r e n c e u p d a t e s t o be done a u t o m a t i c a l l y when d a t a f i e l d s a r e m a i n t a i n e d . In s u c h a s y s t e m i t i s n e c e s s a r y t o e n s u r e t h a t s e c u r i t y i s p r o v i d e d . The d a t a d i c t i o n a r y s h o u l d document t h e a c c e s s t o i t s e l f i n a v a r i e t y of ways. T h e r e s h o u l d be a c l a s s i f i c a -t i o n scheme i d e n t i f y i n g t h e a c c e s s a u s e r s h o u l d h a v e . I t s h o u l d be p o s s i b l e t o s p e c i f y , f o r example, t h a t a u s e r has u p d a t e a c c e s s t o i t e m s b e a r i n g h i s f u n c t i o n as r e s p o n s i b i l i t y and be a b l e t o e n q u i r e i n t o r e l a t e d d e f i n i t i o n s . In a d d i t i o n , t h e s y s t e m s h o u l d a u t o m a t i c a l l y p r o d u c e a u d i t t r a i l s f o r a l l t r a n s a c t i o n s p r o c e s s e d a g a i n s t i t . In s e t t i n g s e c u r i t y l e -v e l s , i t w i l l be n e c e s s a r y f o r t h e d a t a b a s e a d m i n i s t r a t o r t o a n a l y s e t h e r i s k of f r a u d u l e n t d a t a use and t o s e t s e c u r i t y l e v e l s t o e n s u r e t h e l e v e l o f s e c u r i t y d e s i r e d c an be main-1 20 t a i n e d . D a t a D i e t i o n a r y E n v i r o n m e n t E n v i r o n m e n t c r i t e r i a c o n s i d e r e d i n e v a l u a t i n g s o f t w a r e i n c l u d e programming l a n g u a g e , f i l e s t r u c t u r e s u s e d , hardware s u p p o r t e d and ven d o r s u p p o r t . T h e r e a r e two t y p e s of d a t a d i c t i o n a r y s y s t e m s i n e x i s -t e n c e . 3 3 The f i r s t i s a s y s t e m w h i c h i s meant t o f u n c t i o n i n an e n v i r o n m e n t w h i c h may o r may n o t i n c l u d e a d a t a b a s e manage-ment s y s t e m . T h i s t y p e of s y s t e m may have i n t e r f a c e u t i l i t i e s f o r one o r more d a t a b a s e management s y s t e m s . The s e c o n d t y p e o f s y s t e m i s one w h i c h has been d e s i g n e d t o s u p p o r t a p a r t i c u -l a r DBMS. An example of t h i s t y p e o f d a t a d i c t i o n a r y i s UCC-10 w h i c h s u p p o r t s IMS. U n l e s s t h e e n t e r p r i s e c a n e n s u r e t h a t o n l y a s i n g l e d a t a b a s e management s y s t e m w i l l be u s e d , t h e f r e e - s t a n d i n g d a t a d i c t i o n a r y o f f e r s more f l e x i b i l i t y . In a s i n g l e DBMS e n v i r o n m e n t , however, t h e r e i s no need t o s u p p o r t t h e e x t r a c o m p l e x i t y i n v o l v e d i n a f r e e - s t a n d i n g d a t a d i c -t i o n a r y s y s t e m . The d a t a d i c t i o n a r y s y s t e m c a n be w r i t t e n i n one of t h r e e f o r m a t s . F i r s t , i n b a s i c a s s e m b l e r l a n g u a g e ( B A L ) , s e c o n d , i n a h i g h l e v e l l a n g u a g e s u c h as PL/1 o r COBOL, and t h i r d a s an 3 3 B r i t i s h Computer S o c i e t y , pp. 11-4. 121 a p p l i c a t i o n u s i n g a DBMS. As f o r any s o f t w a r e p a c k a g e s , t h e i m p l e m e n t a t i o n l a n g u a g e i s u s u a l l y e v a l u a t e d on c r i t e r i a s u c h a s m a i n t a i n a b i l i t y and s p e e d . A l t h o u g h BAL c a n be o p t i m i z e d t o e x e c u t e more q u i c k l y , i t s m a i n t a i n a b i l i t y i s f a i r l y low. A d a t a d i c t i o n a r y b a s e d on a DBMS has b o t h p r o and con ar g u m e n t s . 3 * In f a v o u r o f i m p l e m e n t a t i o n o f t h e d a t a d i c -t i o n a r y i n a DBMS a r e t h e f l e x i b i l i t y of d e s i g n t h a t t h e DBMS a l l o w s , t h e e f f i c i e n c i e s i n random p r o c e s s i n g w h i c h a r e a l -r e a d y b u i l t i n t o t h e DBMS a c c e s s methods, t h e a v a i l a b i l i t y of o n - l i n e e n q u i r y and u p d a t e , t h e e a s e of p r o d u c i n g ad hoc r e -p o r t s , and t h e a b i l i t y t o c l o s e l y c o u p l e t h e d a t a d i c t i o n a r y and d a t a b a s e management s y s t e m s . Some o f t h e arguments a g a i n s t i m p l e m e n t i n g t h e d a t a d i c -t i o n a r y i n DBMS a r e t h a t t h e d a t a d i c t i o n a r y w i l l be l e s s p o r -t a b l e ( s u c h t h a t i f a hardware change i s made, one would r e -q u i r e hardware where t h e d a t a b a s e management s y s t e m o p e r a t e s ) , t h e r e q u i r e m e n t t o p u r c h a s e a p a r t i c u l a r d a t a b a s e management s y s t e m , and t h e d e v e l o p m e n t of e x p e r t i s e i n t h e m a i n t e n a n c e o f t h e d a t a b a s e management s y s t e m a s w e l l a s t h e d a t a d i c t i o n a r y . I f t h e d a t a d i c t i o n a r y i s o f f e r e d by a ven d o r of a DBMS, t h e m a n u f a c t u r e r w i l l l i k e l y n o t o f f e r i n t e r f a c e s t o o t h e r d a t a -b a s e management s y s t e m s . T h i s i s t r u e f o r a l l s y s t e m s we have 3 " G e o r g e . S c h u s s e l , "The R o l e o f t h e D a t a D i c t i o n a r y , " D a t a m a t i o n , 23, No. 6 ( 1 9 7 7 ) , 129-42; J a c k E. Ewers, "How t o E v a l u a t e a D a t a D i c t i o n a r y , " C o m p u t e r w o r l d , 25, No. 10 ( 1 9 8 1 ) , In D e p t h 1-12. 1 22 r e v i e w e d . I f t h e s y s t e m i s w r i t t e n i n a h i g h l e v e l programming l a n -guage, i n v e s t i g a t i o n s s h o u l d be made t o e n s u r e t h a t t h e d e s i g n of t h e programs i s w e l l s t r u c t u r e d . 3 5 T h i s w i l l i n d i c a t e t h e e a s e of p r o g r a m c o r r e c t i o n due t o e r r o r s i n t h e c o d e . S o u r c e code a v a i l a b i l i t y i s a l s o i m p o r t a n t a s i t a l l o w s f o r t h e d i a g -n o s i s and c o r r e c t i o n o f e r r o r s t h a t a r e f o u n d d u r i n g e x e c u -t i o n . T h i s may be a drawback i n t h a t u s e r m o d i f i c a t i o n s c o u l d make v e n d o r u p d a t e d i f f i c u l t , o r v o i d m a i n t e n a n c e a g r e e m e n t s . The s o f t w a r e s h o u l d use s t a n d a r d f i l e s t r u c t u r e s . T h i s a l l o w s f o r program a c c e s s o f t h e d a t a d i c t i o n a r y f i l e s , and i s l e s s l i k e l y t o be made o b s o l e t e by m o d i f i c a t i o n s t o t h e o p e r a -t i n g s y s t e m . F i n a l l y , s t a n d a r d j o b c o n t r o l l a n g u a g e s t a t e -ments s h o u l d be i n c l u d e d f o r b o t h i n i t i a l l o a d i n g and p r o d u c -t i o n e x e c u t i o n o f t h e d a t a d i c t i o n a r y . Two major f a c t o r s s h o u l d be c o n s i d e r e d c o n c e r n i n g t h e hardware on wh i c h t h e p a c k a g e e x e c u t e s . F i r s t , t h a t t h e s o f t -ware e x e c u t e s on c u r r e n t or p r o p o s e d hardware c o n f i g u r a t i o n s . In e v a l u a t i n g t h i s c r i t e r i a , i t i s a d v i s e d t h a t t h e p u r c h a s e r speak t o u s e r s t h a t a r e p r e s e n t l y u s i n g t h e sytem on a c o n f i -g u r a t i o n s i m i l a r t o t h a t p r o p o s e d . T h i s w i l l e n s u r e t h a t t h e s y s t e m n o t o n l y e x e c u t e s on t h i s t y p e of s y s t e m , but i t a l s o a l l o w s f o r d i s c u s s i o n t o i d e n t i f y any p r o b l e m s o r s p e c i a l mo-3 5 Ewers, In D e p t h p. 5. 123 e d i f i c a t i o n s n e c e s s a r y t o use t h e s y s t e m i n p r o d u c t i o n . T h i s s h o u l d be done f o r c u r r e n t and p r o p o s e d hardware c o n f i g u r a -t i o n s . The d i s c u s s i o n s h o u l d a l s o i n c l u d e i n v e s t i g a t i o n of s p e c i a l h ardware f e a t u r e s u s e d f o r s p e e d o r i n f o r m a t i o n d e n s i -t y , s u c h as m i c r o c o d e o r c a c h e memory. The s y s t e m must a l s o o p e r a t e under p r e s e n t and p r o p o s e d o p e r a t i n g s y s t e m s . I f o t h e r u s e r s have c o n v e r t e d from t h e p r e s e n t s y s t e m t o t h e p r o -p o s e d s y s t e m , t h e y may have d e v e l o p e d c o n v e r s i o n a i d s o r have i d e n t i f i e d s p e c i f i c p r o b l e m s i n t h e c o n v e r s i o n w h i c h c o u l d a i d i n a more s u c c e s s f u l e f f o r t . The s e c o n d hardware c r i t e r i a i s t h e e f f i c i e n c y i n w h i c h t h e s o f t w a r e package u s e s t h e hardware r e s o u r c e s . 3 6 F a c t o r s of e f f i c i e n t hardware use i n c l u d e c o r e u t i 1 i z a t i o n , o n - l i n e s t o r a g e n e c e s s a r y , s y s t e m o v e r h e a d , t h e s i z e o f t h e o n - l i n e m o n i t o r and e x e c u t i v e program, and t h e amount o f s y s t e m t i m e n e c e s s a r y t o e x e c u t e s y s t e m m a i n t e n a n c e t r a n s a c t i o n s s u c h as a d d s , c h a n g e s , d e l e t i o n s and o t h e r s t a n d a r d s y s t e m commands. Ven d o r s u p p o r t may be more o r l e s s i m p o r t a n t d e p e n d i n g on t h e s i z e o f t h e d a t a p r o c e s s i n g d e p a r t m e n t , and t h e e x t e n t t o w h i c h s u p p o r t of t h e d a t a d i c t i o n a r y p a ckage i s done i n t e r n a l -l y . 3 7 I t may be t h a t t h e q u a l i t y o f t h e s o f t w a r e i s an o v e r -r i d i n g f a c t o r . C l e a n s o f t w a r e , w h i c h i s s t r u c t u r e d and w e l l 3 6 Adam, pp. 46-51. 3 7 Ewers, In D e p t h pp. 5-6. 124 documented, w i l l a l l o w a s o p h i s t i c a t e d d a t a p r o c e s s i n g d e p a r t -ment t o s u p p o r t t h e p r o d u c t . The p u r c h a s e d d a t a d i c t i o n a r y s y s t e m may be a b a s i s f o r e x t e n s i v e i n t e r n a l m o d i f i c a t i o n . However, where t h e p u r c h a s e r i s l o o k i n g f o r a good f i t ; one w h i c h s a t i s f i e s a l l of t h e r e q u i r e d f u n c t i o n s , p o s s e s s e s a m a j o r i t y of t h e d e s i r a b l e f u n c t i o n s and some of t h e f u n c t i o n s h e / s h e deems a t t r a c t i v e , and do e s not p l a n t o p r o v i d e e x t e n -s i v e i n h o u s e m a i n t e n a n c e , a h i g h l e v e l of v e n d o r s u p p o r t i s n e c e s s a r y . V endor s u p p o r t s h o u l d i n c l u d e l o c a l s u p p o r t , o r a h o t l i n e ( p r o b l e m l i n e ) w h i c h i s a v a i l a b l e 24 h o u r s a d a y . T h i s i n d i c a t e s t h a t b a s i c s u p p o r t i s p r e s e n t . The p u r c h a s e r s h o u l d examine t h e d o c u m e n t a t i o n t o e n s u r e t h a t t h e minimum d o c u m e n t a t i o n i s p r e s e n t . T h i s would i n c -l u d e : 1. O v e r v i e w of s y s t e m f u n c t i o n s . A h i g h l e v e l f l o w c h a r t of s y s t e m o p e r a t i o n and s t r u c t u r e c h a r t s o r o t h e r s i m i -l a r g r a p h i c e x h i b i t s d o c u m e n t i n g t h e p r o c e s s i n g o f t h e s y s t e m . 2. D e s c r i p t i o n of t h e t e c h n i c a l f e a t u r e s o f t h e s y s t e m , i n c l u d i n g d o c u m e n t a t i o n o f any s p e c i a l i z e d t e c h n i c a l p r o c e d u r e s w h i c h a r e i n c o r p o r a t e d i n t o t h e p r o g r a m s . 3. D e s c r i p t i o n of f i l e s t r u c t u r e s , c o m p r i s i n g f i l e l a y o u t s , a c c e s s methods, and any s p e c i a l d a t a - r e l a t e d t o p i c s s u c h 1 25 as l o g g i n g of t r a n s a c t i o n s , backup or r e c o v e r y . 4. A summary of each program i n the system, i d e n t i f y i n g i n p u t s , o u t p u t s , a n a r r a t i v e of p r o c e s s i n g , any subrou-t i n e s used, and a f u n c t i o n c h a r t i d e n t i f y i n g the f l o w of p r o c e s s i n g . 5. Data i n p u t i n s t r u c t i o n s . T h i s would embrace d e t a i l e d d e s c r i p t i o n s of i n p u t d a t a , documentation of i n p u t s c r e e n s used, examples of forms n e c e s s a r y t o support the system, and e r r o r messages and t h e i r r e s o l u t i o n . 6. A d e s c r i p t i o n of r e p o r t s . T h i s s h o u l d i n c l u d e examples of a l l r e p o r t s which i d e n t i f y t h e i r f u n c t i o n and con-t e n t s , and a d e s c r i p t i o n of how the r e p o r t has been p r o -duced. The best way t o v e r i f y vendor s u p p o r t i s t o d i s c u s s i t w i t h some of the u s e r s of the s o f t w a r e . 3 8 Some of the t o p i c s which s h o u l d be c o v e r e d i n c l u d e : 1. The r e l i a b i l i t y and ease of i n s t a l l a t i o n of f i x e s t o the system. A system which has t o be unloaded and r e l o a d e d f o r each f i x t o be i n s t a l l e d , and which does not come w i t h s u f f i c i e n t s o f t w a r e t o do such an o p e r a t i o n , can be Ewers, In Depth pp. 5-6; Adam, p. 51. 126 cumbersome t o m a i n t a i n . 2. The f r e q u e n c y of enhancements. T h i s i n d i c a t e s an on-g o i n g i n t e r e s t by the;-- v e n d o r t o upgrade t h e s o f t w a r e p a c k a g e . I f t h e s e enhancements have been done b a s e d on u s e r r e q u e s t s , t h e n c o n t i n u e d good r e l a t i o n s h i p s w i t h t h e v e n d o r a r e i m p l i e d . The e x i s t e n c e o f a u s e r - g r o u p would a l s o i n d i c a t e good c o m m u n i c a t i o n s between t h e v e n d o r and t h e u s e r s . 3. The a v a i l a b i l i t y and e x t e n s i v e n e s s of t r a i n i n g . U s e r s a r e b e s t a b l e t o i d e n t i f y good and bad p o i n t s c o n c e r n i n g t h e v e n d o r ' s t r a i n i n g p r o g r a m . E x t e n s i v e t r a i n i n g d u r i n g t h e i n s t a l l a t i o n and beyond, as new p e r s o n n e l a r e h i r e d , s h o u l d be a v a i l a b l e . T r a i n i n g a f t e r enhancements have been made t o t h e s o f t w a r e would a l s o be d e s i r a b l e . F i n a l l y , i n e v a l u a t i n g s o f t w a r e p a c k a g e s t h e p u r c h a s e r may r e q u i r e a s p e c i f i c t y p e o f payment scheme. 3 9 I t s h o u l d be p o s s i b l e t o - l e a s e or p u r c h a s e t h e s o f t w a r e , m a i n t e n a n c e f e e s and m a i n t e n a n c e c o n t r a c t s s h o u l d be i n s p e c t e d , and a r e v i e w s h o u l d be made of t h e p o s s i b i l i t y o f c a n c e l l a t i o n and p e n a l t i e s w h i c h c o u l d be i n c u r r e d . 3 9 Adam, p. 51. 1 27 5.3 I m p l e m e n t a t i o n The p o s s i b i l i t y o f a s u c c e s s f u l i m p l e m e n t a t i o n c a n be i n c r e a s e d by c h o o s i n g an i m p l e m e n t a t i o n p e r i o d w h i c h w i l l show immediate b e n e f i t s of a d a t a d i c t i o n a r y s y s t e m . " 0 T h e r e a r e f o u r i n s t a n c e s when a d a t a d i c t i o n a r y s y s t e m i m p l e m e n t a t i o n c a n p r o v i d e s u c h b e n e f i t s : 1. When t h e d a t a p r o c e s s i n g o p e r a t i o n has become complex, and t h e p r o p o s e d a p p l i c a t i o n s y s t e m s d e v e l o p m e n t p r o -j e c t s p r o p o s e d a r e not c r i t i c a l . 2. B e f o r e a m a j o r d a t a b a s e management s y s t e m c o n v e r s i o n e f f o r t . 3. B e f o r e u n d e r t a k i n g a l a r g e s y s t e m s d e v e l o p m e n t p r o j e c t . 4. As p a r t o f an o n g o i n g d a t a p r o c e s s i n g s t a n d a r d s p r o j e c t . In a mature d a t a p r o c e s s i n g e n v i r o n m e n t , where t h e main-t e n a n c e a c t i v i t y may o c c u p y more t h a n 50 p e r c e n t o f d a t a p r o -c e s s i n g s t a f f t i m e , t h e i m p l e m e n t a t i o n of a d a t a d i c t i o n a r y may have b e n e f i t s . " 1 T h e r e a r e two o b j e c t i v e s i n u n d e r t a k i n g t h i s t y p e o f o n g o i n g p r o j e c t : "° C a n n i n g , p. 11; Ewers, In D e p t h p. 4. 4 1 N o l a n , p. 101; C a n n i n g p. 9. 1 28 1. To c l e a n up t h e c o n f u s i o n i n t h e d a t a . 2. To a i d u s e r s i n i d e n t i f y i n g enhancements and s y s t e m s p r o b l e m s . In a mature e n v i r o n m e n t , where o p e r a t i o n s o r i e n t e d s y s -tems have been implemented t o s u p p o r t s t a n d a r d b u s i n e s s f u n c -t i o n s , t h e e n v i r o n m e n t i s l i k e l y t o c o n s i s t o f a number o f s e p a r a t e a p p l i c a t i o n p a c k a g e s e a c h u s i n g numerous d i s c and t a p e f i l e s , u n l e s s t h e o r g a n i z a t i o n has u s e d a c o m p r e h e n s i v e s y s t e m s m e t h o d o l o g y w h i c h i n c l u d e d s y s t e m s p l a n n i n g and d a t a m o d e l l i n g . The o r g a n i z a t i o n may a l s o have a c q u i r e d a d a t a b a s e management s y s t e m and some a p p l i c a t i o n s may use a DBMS as an a c c e s s s y s t e m . T h i s w i l l i n e v i t a b l y r e s u l t i n poor d a t a s h a r i n g , and r e d u n d a n t , i n c o n s i s t e n t d a t a . Once some o r d e r has been e s t a b l i s h e d i n t h e s p e c i f i c a t i o n of d a t a and p r o c e s s i n g e n t i t i e s , t h e s e c o n d o b j e c t i v e c a n be p u r s u e d , t h a t i s , t h a t t h e d a t a d i c t i o n a r y a i d u s e r s of t h i s i n f o r m a t i o n . The b e n e f i t w h i c h c a n be c i t e d h e r e i s t h e a b i -l i t y t o l o o k up a p p r o v e d d a t a d e f i n i t i o n s and i d e n t i f y t h e manner i n w h i c h t h e y a r e a c c e s s e d , where t h e y a r e a c c e s s e d , and t h e t y p e s of r e l a t i o n s h i p s between d a t a and p r o c e s s i n g e n t i t i e s . In p u r s u i n g t h i s b e n e f i t , t h e d a t a b a s e a d m i n i s t r a t o r s h o u l d promote the d e s i r e t o c r e a t e d e s c r i p t i o n s w h i c h a r e r e a d i l y and s e l e c t i v e l y r e t r i e v a b l e t h r o u g h t h e use of d a t a 129 d e s c r i p t o r s and c r o s s - r e f e r e n c e r e p o r t s . In p r o v i d i n g t h e s e f e a t u r e s t h e d a t a d i c t i o n a r y w i l l r e q u i r e s e c u r i t y and p r i v a c y c o n t r o l s t o e n s u r e t h e d a t a d i c t i o n a r y ' s i n t e g r i t y and t o l i m i t t h e a c c e s s t o a u t h o r i z e d u s e r s . A key p o i n t i s t h a t o n g o i n g d a t a d i c t i o n a r y m a i n t e n a n c e i s s i g n i f i c a n t and t h e c r e a t i o n and s t a f f i n g of a d a t a b a s e a d m i n i s t r a t o r f u n c t i o n , w h i c h has r e s p o n s i b i l i t y f o r t h e d a t a d i c t i o n a r y , i s paramount. " C l e a r l y , an o u t - o f - d a t e d a t a d i c -t i o n a r y w i l l be u s e l e s s " . 4 2 The s e c o n d major e v e n t w h i c h c an be u s e d t o promote t h e i n s t a l l a t i o n o f a d a t a d i c t i o n a r y s y s t e m i s t h e i n s t a l l a t i o n of a d a t a b a s e management s y s t e m . B e f o r e t h i s i s done, i t i s n e c e s s a r y t o p e r f o r m a t h o r o u g h a n a l y s i s of d a t a e n t i t i e s and i d e n t i f y t h e i r r e l a t i o n s h i p s . In a d d i t i o n , t h e DBA w i l l n eed t o e x p l o r e a l t e r n a t i v e d a t a b a s e s t r u c t u r e s i n d e v e l o p i n g an o p t i m a l d a t a b a s e f o r m a t . In s u p p o r t i n g t h i s t y p e of a n a l y s i s , t h e d a t a d i c t i o n a r y would r e q u i r e one o r more d a t a b a s e l i n k s . I f t h e d a t a b a s e management s y s t e m has a l r e a d y been i d e n t i f i e d , a d a t a d i c -t i o n a r y w h i c h s u p p o r t s t h a t DBMS i s n e c e s s a r y . The d a t a d i c -t i o n a r y s h o u l d be a m e t a d a t a d i c t i o n a r y t o a l l o w t h e d e f i n i -t i o n o f d a t a , p r o c e s s e s and r e l a t i o n s h i p s a t a h i g h l e v e l , a nd 4 2 John J . C a h i l l , "A D i c t i o n a r y / D i r e c t o r y Method f o r B u i l d i n g A Common MIS Data B a s e , " J o u r n a l o f Systems Management, 21 (Nov. 1970), 29. 1 30 have f a c i l i t i e s t o a l l o w f o r t h e a u t o m a t i c g e n e r a t i o n of t h e DBMS d e f i n i t i o n . The p r o b l e m s o f c o n t r o l and m o n i t o r i n g p e r f o r m a n c e on l a r g e s y s t e m s d e v e l o p m e n t p r o j e c t s p r o v i d e t h e t h i r d o p p o r -t u n i t y f o r t h e use o f a d a t a d i c t i o n a r y s y s t e m . The d a t a d i c -t i o n a r y s y s t e m c a n r e d u c e t h e s y s t e m d e v e l o p m e n t e f f o r t by i d e n t i f y i n g t h e c o n c e p t u a l d e s i g n and p r o v i d i n g d o c u m e n t a t i o n f o r f u n c t i o n s and d a t a models a t an e a r l y s t a g e . A d a t a d i c -t i o n a r y c a n a s s i s t t h e d e s i g n e r s i n r e s o l v i n g i m p l e m e n t a t i o n d e c i s i o n s , s u c h as t h e s y s t e m ' s s c o p e or i m p l e m e n t a t i o n d a t a -b a s e d e s i g n . The d a t a d i c t i o n a r y can a l s o s u p p l y s u p p o r t i n -f o r m a t i o n t o a l l o w a l t e r n a t e d e s i g n s o f d a t a and programs t o be g e n e r a t e d . Once t h e d e s i g n has been c o m p l e t e d , t h e d a t a d i c t i o n a r y p r o v i d e s a b a s e l i n e by w h i c h c o m p l e t i o n can be measured. In t h i s way, d e v e l o p m e n t c a n be c o n t a i n e d i n t h a t any c h a n g e s t o t h e i m p l e m e n t a t i o n d e s i g n can be a n a l y z e d i n t e r m s of t h e amount of a d d i t i o n a l programming o r d a t a b a s e d e f i n i t i o n work n e c e s s a r y . The d a t a d i c t i o n a r y c a n a l s o r e d u c e t h e amount of p r o -gramming e f f o r t n e c e s s a r y by s u p p l y i n g copy l i b r a r i e s w h i c h c o n t a i n d a t a d e f i n i t i o n s f o r d a t a b a s e s and d a t a d i v i s i o n s o f p r o g r a m s . I n . a d d i t i o n , t h e d a t a d i c t i o n a r y can p r o v i d e s t a n -d a r d code w h i c h c a n be i n c l u d e d i n e d i t modules and p r o v i d e a s i g n i f i c a n t p o r t i o n of t h e d o c u m e n t a t i o n n e c e s s a r y f o r a comp-131 l e t e s y s t e m . F i n a l l y , t h e d a t a d i c t i o n a r y can be u s e d as a t o o l i n a s s i s t i n g an o n g o i n g s t a n d a r d s d e v e l o p m e n t program. In a l a r g e o r g a n i z a t i o n , i t i s n e c e s s a r y t o have e x p l i c i t s t a n -d a r d s . T h e s e s t a n d a r d s a r e d e f i n e d and m a i n t a i n e d by a s t a n -d a r d s f u n c t i o n . A d a t a d i c t i o n a r y c an be one t o o l u s e d by t h e s t a n d a r d s o f f i c e r . In s u p p o r t i n g t h e s t a n d a r d s o f f i c e r , t h e d a t a d i c t i o n a r y r e q u i r e s t h r e e b r i d g e s : 1. An a u t o l o a d f a c i l i t y t o a l l o w d a t a d i c t i o n a r y i n f o r m a -t i o n t o be e x t r a c t e d from p r o g r a m s , d a t a f i l e h a n d l e r s , and d a t a b a s e management s y s t e m s . T h i s b r i d g e s h o u l d be c o m p l e t e , i d e n t i f y i n g d i f f e r e n c e s between s t a n d a r d s do-cumented i n t h e d a t a d i c t i o n a r y and a c t u a l i m p l e m e n t a -t i o n w i t h i n p r o g r a m s . E x c e p t i o n r e p o r t s and s u g g e s t e d c h a n g e s t o programs s h o u l d be g e n e r a t e d . 2. A u t i l i t y w h i c h can s u p p l y d e f i n i t i o n s t o programmers i n forms of copy books, l i b r a r i e s , o r d i r e c t d e f i n i t i o n s p r o v i d e d a t e x e c u t i o n t i m e . 3. A u t i l i t y t o s u p p l y d a t a b a s e management s y s t e m d e f i n i -t i o n s t h r o u g h a copy book l i b a r a r y or a r e a l t i m e i n t e r -f a c e t o t h e d a t a b a s e management s y s t e m . W i t h t h e s e b r i d g e s , t h e s t a n d a r d s o f f i c e r c a n e n s u r e t h a t t h e s y s t e m s b e i n g d e v e l o p e d and t h o s e a l r e a d y i n o p e r a t i o n 1 32 c o n f o r m t o s t a n d a r d s d e f i n e d by t h e o r g a n i z a t i o n . In o r d e r t o e n s u r e t h a t an e n t e r p r i s e has a s u c c e s s f u l i m p l e m e n t a t i o n o f a d a t a d i c t i o n a r y , w h i c h n o t o n l y a c h i e v e s t h e o b j e c t i v e s o f l o a d i n g new d a t a d e f i n i t i o n s and i n f o r m a t i o n c o n c e r n i n g o t h e r e n t i t i e s , but i s a l s o a v i a b l e l o n g t e r m f u n -c t i o n , t h e r e a r e f i v e r e q u i r e m e n t s : 4 3 1 . S e n i o r management must have a commitment t o e s t a b l i s h i n g c o n t r o l of d a t a e n t i t i e s . In t h e l o n g term, t h e d a t a d i c t i o n a r y c a n p r o v i d e i n f o r m a t i o n f o r u t i l i t y p r o g r a m s w h i c h w i l l r e d u c e t h e d e v e l o p m e n t t i m e f o r new s y s t e m s , i n c r e a s e d a t a s h a r i n g between o r g a n i z a t i o n a l e n t i t i e s , and r e d u c e t h e e f f o r t n e c e s s a r y t o m a i n t a i n e x i s t i n g s y s t e m s . The a c h i e v e m e n t o f t h e s e b e n e f i t s can o n l y be a s s u r e d i f t h e i m p l e m e n t a t i o n of t h e d a t a d i c t i o n a r y s y s t e m i s s u c c e s s f u l . T h i s r e q u i r e s a s e n i o r management commi tment. 2. The s e t u p o f an a c t i v e d a t a b a s e a d m i n i s t r a t o r r o l e t o i d e n t i f y and e n f o r c e s t a n d a r d s , and t o t a k e r e s p o n s i b i -l i t y f o r t h e i n t e g r i t y o f t h e d a t a d i c t i o n a r y . The d a -t a b a s e a d m i n i s t r a t o r i s a f u n c t i o n w h i c h i s s t a f f e d by one o r more i n d i v i d u a l s . The d a t a d i c t i o n a r y s h o u l d be t h e f i r s t a p p l i c a t i o n r e s p o n s i b i l i t y f o r t h e d a t a b a s e 4 3 Adam, p. 47. 1 33 a d m i n i s t r a t o r . 3. An h o n e s t e v a l u a t i o n o f t h e c o s t and b e n e f i t s s h o u l d be done. In t h i s e v a l u a t i o n i t s h o u l d be n o t e d t h a t t h e d a t a d i c t i o n a r y i s an a d d i t i o n a l l e v e l o f management and r e s p o n s i b i l i t y . The e f f o r t i n d e v e l o p i n g and main-t a i n i n g a d a t a d i c t i o n a r y w i l l most c e r t a i n l y r e s u l t i n t h e DBA f u n c t i o n and t h e d a t a d i c t i o n a r y , as a c o s t c e n t r e , w i t h l i t t l e c h a n c e of d i r e c t p a y o u t . However, g r o w t h s h o u l d be e a s i e r once t h e d a t a d i c t i o n a r y i s i n p l a c e . F o r example, t h e i n s t a l l a t i o n o f t h e d a t a b a s e management s y s t e m s h o u l d be a more s t r a i g h t f o r w a r d t a s k . 4. S u c c e s s f u l d a t a d i c t i o n a r y i m p l e m e n t a t i o n r e q u i r e s s t r o n g u s e r i n v o l v e m e n t . The u s e r s o f d a t a i n a non d a t a d i c t i o n a r y e n v i r o n m e n t have t h e r e s p o n s i b i l i t y t o t h e m s e l v e s a t l e a s t , o f d e f i n i n g a n d m a i n t a i n i n g t h e d e f i n i t i o n o f d a t a e n t i t i e s . U s e r i n v o l v e m e n t w i l l be n e c e s s a r y t o r e c o n c i l e naming, f o r m a t and d e f i n i t i o n d i f f e r e n c e s o f d a t a w h i c h i s s h a r e d . 5. F i n a l l y , t h e o r g a n i z a t i o n as a whole r e q u i r e s a l o n g t e r m commitment. The t a s k of i n s t a l l i n g a d a t a d i c -t i o n a r y i s b o t h l o n g and t e d i o u s and c a n n e v e r be s a i d t o be 100 p e r c e n t c o m p l e t e as new d a t a and new d e f i n i -t i o n s a r e c o n s t a n t l y b e i n g d e v e l o p e d . In a d d i t i o n , t h e s t a n d a r d s w h i c h a d a t a d i c t i o n a r y imposes a r e r e s t r i c -134 t i v e . Management w i l l p r o b a b l y want t o r o t a t e s t a f f a s s i g n m e n t s w i t h i n t h e d a t a b a s e a d m i n i s t r a t i o n f u n c t i o n and e n s u r e t h a t t e d i o u s t a s k s a r e s h a r e d by a l l . 1 35 CHAPTER 6 CONCLUSION T h i s t h e s i s has examined t h e d a t a d i c t i o n a r y from a number of v i e w p o i n t s : s t r u c t u r a l l y , where we have p r o p o s e d a c l a s s i f i c a t i o n of d a t a d i c t i o n a r y s y s t e m s ; o r g a n i z a t i o n a l l y , where we have r e v i e w e d t h e u s e r s and u s e s of t h e s y s t e m ; and c o m m e r c i a l y , where we have examined f i v e p a c k a g e s i n d e t a i l and two i n o v e r v i e w . F i n a l l y , we have a p p r o a c h e d t h e d i c -t i o n a r y from t h e p r a g m a t i c v i e w p o i n t , a n s w e r i n g t h e q u e s t i o n s : why do we need i t ? , how do we c h o o s e i t ? , and how do we s u c e s -s f u l l y i n s t a l l i t ? W i t h a l l o f t h e b e n e f i t s o f t h e d a t a d i c t i o n a r y s y s t e m , t h e i r a c c e p t a n c e i s f a r from u n i v e r s a l . CINCOM, i n t h e i r l i -t e r a t u r e , i d e n t i f y some p o s s i b l e r e a s o n s : " 4 1. I n s t a l l a t i o n i s an o d i o u s t a s k , where l a r g e amounts of d a t a a r e e n t e r e d . 2. Poor d a t a e n t r y f a c i l i t i e s , u s u a l l y b a t c h , w i t h p o s i -t i o n a l p a r a m e t e r s , and o u t p u t w h i c h i s p r e s e n t e d i n mas-s i v e t a b u l a r r e p o r t s . 3. No t a n g i b l e b e n e f i t t o end u s e r s . C incom S y s t e m s , D a t a C o n t r o l System, ( [ U n i t e d S t a t e s ] : n.p., 1981), n.pag. 1 36 We c a n add t o t h e s e t h e f o l l o w i n g : 1. A l a c k of u t i l i t i e s w h i c h a r e u s e f u l i n r e d u c i n g t h e e f f o r t o f systems d e s i g n , and i m p l e m e n t a t i o n . 2. O f t e n no Data Base A d m i n i s t r a t o r f u n c t i o n i s s e t up, l e a v i n g t h e r e s p o n s i b i l i t y f o r t h e d i c t i o n a r y u n c l e a r . 3. An o v e r - a m b i t i o u s i m p l e m e n t a t i o n p l a n , o f t e n t o l o a d a l l o f t h e e n t e r p r i s e ' s d e f i n i t i o n s a t o n c e . The d a t a d i c t i o n a r y s y s t e m s r e v i e w e d i n C h a p t e r 4, e s p e -c i a l l y t h o s e w h i c h have been m o d i f i e d and u p d a t e d i n t h e l a s t y e a r , show g r e a t a d v a n c e s i n r e s p o n d i n g t o t h e s e c r i t i c i s m s . F o l l o w i n g t h e i n s t a l l a t i o n g u i d e l i n e s we p r e s e n t e d i n C h a p t e r 5, a r e d u c e d s c o p e of d a t a i n p u t , one w h i c h w i l l show b e n e f i t s t o an a s s o c i a t e d p r o j e c t ( s u c h as a DBMS i n s t a l l a t i o n ) , i s s u g g e s t e d . The u t i l i t i e s w h i c h a l l o w d a t a t o be e x t r a c t e d from e x i s t i n g programs a l s o a s s i s t s i n s o l v i n g t h e p r o b l e m s of a t t e m p t i n g t o do t o o much a t once, w i t h o u t a c l e a r l y p e r c e i v e d b e n e f i t . S e v e r a l p a c k a g e s now s u p p o r t o n l i n e d a t a e n t r y w i t h u s e r -f r i e n d l y menues, p r o m p t i n g and t u t o r i a l f e a t u r e s . I n p u t i s f r e e form, r e l y i n g on keywords r a t h e r t h a n p o s i t i o n a l parame-t e r s . B e n e f i t s t o end u s e r s c an be f o u n d i n r e d u c e d a p p l i c a t i o n d e v e l o p m e n t and m a i n t e n a n c e t i m e , and a s s u r a n c e t h a t a more c o m p l e t e l y d e f i n e d s y s t e m w i l l r e s u l t f r o m t h e d e s i g n e f f o r t . 1 37 T h e s e b e n e f i t s a r e s u p p o r t e d by u t i l i t i e s s u c h a s o n - l i n e q u e r y l a n g u a g e s w h i c h a l l o w t h e a n a l y s t t o examine t h e c o n c e p -t u a l d e s i g n , i d e n t i f y i n g unanswered q u e s t i o n s , and s o u r c e code g e n e r a t i o n t o a s s i s t t h e programmer i n t h e d e v e l o p m e n t and m a i n t e n a n c e of p r o g r a m s . T e s t d a t a g e n e r a t o r s , d a t a use maps and a u t o m a t e d d a t a b a s e g e n e r a t o r s a l s o a s s i s t i n s y s t e m d e v e -lopment and m a i n t e n a n c e . D a t a d i c t i o n a r i e s have r e c e n t l y begun t o e v o l v e i n a d i f -f e r e n t d i r e c t i o n . A good a p p r e c i a t i o n of t h e t y p e s of e n t i -t i e s t o be s u p p o r t e d was w e l l documented i n ANSI and BCS pub-l i c a t i o n s . P a c k a g e s a v a i l a b l e t o d a y r e f l e c t t h a t d e s i g n . What r e m a i n s i s t h e d e v e l o p m e n t of f a c i l i t i e s t o use t h i s i n -f o r m a t i o n c o m p l e t e l y . " D a t a Management Sy s t e m s " (DMS) ( n o t t o be c o n f u s e d w i t h D a t a Base Management Systems (DBMS)), a r e t h e d a t a d i c t i o n a r y s y s t e m s of tomorrow. 4 5 DMS a r e composed o f f o u r main s o f t w a r e s y s t e m s : 1. A s i m p l i f i e d d a t a d i c t i o n a r y . 2. A s c r e e n d e s i g n a i d . 3. A d a t a b a s e management s y s t e m . 4. A s i m p l i f i e d p r o g r a m l a n g u a g e . DMS were d e v e l o p e d t o a s s i s t end u s e r s i n d e v e l o p i n g s y s t e m s , " 5 R i c h a r d G. C a n n i n g , e d . , "A New View of Data D i c t i o n a r i e s , " EDP A n a l y z e r , 19, No. 7 ( 1 9 8 1 ) . 1 38 u s u a l l y on m i n i or m i c r o computers. T h e i r d a t a d i c t i o n a r i e s c o n t a i n l i t t l e e l s e except name, p i c t u r e and output f o r m a t . The s c r e e n d e s i g n a i d a l l o w s the d e v e l o p e r t o s p e c i f y the d a t a and i t s l o c a t i o n on the s c r e e n . The programming language has b a s i c i n p u t , m o d i f y , and d e l e t e l o g i c t o support the main-tenance of d a t a , a s i m p l e r e p o r t g e n e r a t o r t o l i s t and s e l e c t d a t a , a g a i n s p e c i f y i n g the names of d a t a s t o r e d i n the d a t a d i c t i o n a r y . A d d i t i o n a l f e a t u r e s , t o s u b t o t a l and perhaps p e r -form s t a t i s t i c a l f u n c t i o n s , may a l s o be a v a i l a b l e . The s p e c i -f i c a t i o n s a re o f t e n t r a n s l a t e d i n t o a p r o c e d u r a l language such as COBOL, so t h a t more complex p r o c e d u r e s can be added i f needed. We b e l i e v e t h a t the d a t a d i c t i o n a r y of the f u t u r e w i l l p a r t i c i p a t e i n t h i s type of o r g a n i z e d data p r o c e s s i n g system. A d d i t i o n a l u t i l i t i e s and f e a t u r e s a re n e c e s s a r y t o p r o v i d e a system which a d d r e s s s e s each u s e r ' s needs. These f u n c t i o n s have been d e s c r i b e d i n C h a p t e r s 3 and 5. Through the use of a data d i c t i o n a r y , the c h a r a c t e r i s t i c s of management of an i n f o r m a t i o n source can be r e a l i z e d . " 6 F i r s t , an i n f o r m a t i o n system can be o p p o r u t u n i t y d r i v e n r a t h e r than t e c h n o l o g i c a l l y or f u n c t i o n a l l y d r i v e n because d e v e l o p -ment t r a d e o f f s can be a n a l y z e d i n the c o n c e p t u a l d a t a frame-work. In t h i s way i n f o r m a t i o n t h a t i s n e c e s s a r y w i l l be d e l i -4 6 Joseph F e r r e i r a , "IRM: An E v o l u t i o n a r y M o s a i c , " I n f o s y s t e m s , 26, No. 10 (1979), 86. 1 39 v e r e d b e f o r e t h a t w h i c h i s e a s y t o d e v e l o p . S e c o n d l y , t h e i n f o r m a t i o n r e s o u r c e c a n be u s e r d o m i n a t e d r a t h e r t h a n a n a l y s t d o m i n a t e d . U s e r s can i d e n t i f y i n f o r m a t i o n n e c e s s a r y f o r t h e c o m p l e t i o n o f t h e i r d u t i e s by a n a l y z i n g t h e c o n c e p t u a l s t r u c t u r e and a c c e s s i n g i n f o r m a t i o n t h e y r e q u i r e . U s e r a n a l a y s t s and t e c h n i c a l a n a l y s t s c a n t h e n c o o p e r a t e i n d e v e l o p i n g t h e p r o p e r i m p l e m e n t a t i o n s t r u c t u r e s n e c e s s a r y t o p r e p a r e t h e i n f o r m a t i o n r e q u i r e d . T h i r d , d a t a can be d y n a m i c a l l y r a t h e r t h a n r i g i d l y s t r u c -t u r e d . D a t a i n d e p e n d e n c e can be a c h i e v e d by u s i n g t h e d a t a d i c t i o n a r y as an i n t e r f a c e between programs and t h e d a t a b a s e management sy s t e m . The d a t a d i c t i o n a r y c a n s e l e c t i v e l y r e -t r i e v e and p r o v i d e d a t a i n t h e f o r m a t w h i c h t h e program r e -q u i r e s , and a l l o w f o r use of d a t a w i t h d i f f e r i n g v i e w s . Some d a t a i n d e p e n d e n c e i s a l r e a d y p r o v i d e d by d a t a b a s e management sytems and t h e use of schemas and subschemas. However, a d a t a d i c t i o n a r y can i n t e r f a c e between a s i n g l e p r o g r a m and s e v e r a l d a t a b a s e management s y s t e m s , o r c o n v e n t i o n a l f i l e s t u c t u r e s , i n p r o v i d i n g t h e d a t a t h a t a p r o g ram r e q u i r e s . F o u r t h , the s y s t e m can be a d m i n i s t r a t i v e l y c o n s t r a i n e d r a t h e r t h a n t e c h n o l o g i c a l l y l i m i t e d . By i d e n t i f y i n g t h e a c t u a l r e q u i r e m e n t s o f an e n t e r p r i s e , s y s t e m s p l a n n e r s can i d e n t i f y t h o s e f u n c t i o n s w h i c h need s u p p o r t . T h i s i s i n marked c o n t r a s t t o s y s t e m s w h i c h a r e i m p l e m e n t e d m e r e l y be-c a u s e o f t e c h n o l o g i c a l a d v a n c e . Good examples o f t h i s t y p e of 1 40 s y s t e m a r e o n - l i n e b a n k i n g s y s t e m s w h i c h have t r a d i t i o n a l l y shown t h a t t h e y have v e r y l i t t l e b e n e f i t i n t e r m s of l a b o u r s a v i n g s and p r o v i d e i n f o r m a t i o n a t a much more t i m e l y r a t e t h a n i s n e c e s s a r y . The d a t a d i c t i o n a r y c a n a s s i s t t h e e n t e r -p r i s e i n d e v e l o p i n g a p p l i c a t i o n sytems w h i c h a r e r e s u l t and p r o c e s s o r i e n t e d . By i d e n t i f y i n g and d o c u m e n t i n g d a t a and p r o c e s s i n g e n t i t i e s , t h e d a t a d i c t i o n a r y c a n a s s i s t management i n i d e n t i f y i n g t h o s e a r e a s w h i c h r e q u i r e i n f o r m a t i o n , and p r o -v i d i n g t h a t i n f o r m a t i o n , r a t h e r t h a n a l l o w i n g s y s t e m s t o be d e v e l o p e d by i d e n t i f y i n g f u n c t i o n s w h i c h a r e i n c r i s i s and a t t e m p t i n g t o s o l v e t h a t c r i s i s . 141 BIBLIOGRAPHY Adam, R o b e r t G. "Data D i c t i o n a r i e s : F o r T h a t M a t u r e Look." D a t a Management, 17, No. 10 ( O c t . 1979), 46-51. ANSI/X3/SPARC S t u d y Group on D a t a b a s e Management Systems, " I n t e r i m R e p o r t . " FDT, 7, No. 2 ( 1 9 7 5 ) . B r i t i s h Computer S o c i e t y . "Data D i c t i o n a r y Systems W o r k i n g P a r t y R e p o r t . " D a t a B a s e , 9, No. 4 ( 1 9 7 7 ) . C a h i l l , John J . "A D i c t i o n a r y / D i r e c t o r y Method f o r B u i l d i n g a Common MIS D a t a B a s e . " J o u r n a l of Systems Management, 21 (November, 1970) 23-9. C a n n i n g , R i c h a r d G. ed. " I n s t a l l i n g a D a t a D i c t i o n a r y . " EDP  A n a l y z e r , 16, No. 1 ( 1 9 7 8 ) . « A N e w V i e w 0 f D a t a D i c t i o n a r i e s . " EDP A n a l y z e r , 19, No. 7 ( 1 9 8 1 ) . C h a m b e r l a i n , R o b e r t B. "DBMS and Data D i c t i o n a r y : To Merge o r N o t ? " C o m p u t e r w o r l d , 29 O c t . 1979, p. 36; p. 38. Cinc o m S y s t e m s . D a t a C o n t r o l System. [ U n i t e d S t a t e s ] : n . p . , 1981. C u r t i c e , R o b e r t M. and E . M a r t i n D ieckmann. "A S u r v e y o f D a t a D i c t i o n a r i e s . " D a t a m a t i o n , March 1981, pp.135-56. 142 D a v e n p o r t , R.A. "The D e s i g n of D i s t r i b u t e d D a t a Base S y s t e m s . " Computer J o u r n a l , 24, No. 1 ( 1 9 8 1 ) , 31-41. Ewers, J a c k E. "How t o E v a l u a t e a D a t a D i c t i o n a r y . C o m p u t e r w o r l d , 25, No. 10 ( 1 9 8 1 ) , In D e p t h 1-12. F e r r e i r a , J o s e p h . "IRM: An E v o l u t i o n a r y M o s a i c . " I n f o s y s t e m s , 26, No. 10 ( 1 9 7 9 ) , 86. H u f f e n b e r g e r , M.A. "The D e s i g n of D a t a E l e m e n t s : A D a t a Base P e r s p e c t i v e . " P r o c e e d i n g s of t h e Symposium on Management  of D a t a E l e m e n t s i n I n f o r m a t i o n P r o c e s s i n g . G a t h e r s b u r g , M a r y l a n d : n.p., 1975, pp. 99-112. K r e i t z e r , Lawrence W. "Data D i c t i o n a r i e s - The H e a r t o f IRM." . I n f o s y s t e m s , 28, No. 2 ( 1 9 8 1 ) , 64; 66. L e f k o v i t s , Henry C. D a t a D i e t i o n a r y S y s t e m s . W e l l e s l e y : Q . E . D I n f o r m a t i o n S c i e n c e s , 1977. Leong-Hong, B e l k i s , and B e a t r i c e M a r r o n . T e c h n i c a l P r o f i l e of  Seven D a t a E l e m e n t D i c t i o n a r y / D i r e c t o r y S y s t e m s . N a t i o n a l B u r e a u o f S t a n d a r d s S p e c i a l P u b l i c a t i o n 500-3; W a s h i n g t o n , D.C.:GPO, 1977. Lomax, J.D. D a t a D i c t i o n a r y . S y s t e m s . L o n d o n : N a t i o n a l Computing C e n t e r , 1977. L y o n , John K. The D a t a b a s e A d m i n i s t r a t o r . New Y o r k : John W i l e y & Sons, 1976. 143 M a r t i n , G e o r g e . "Data D i c t i o n a r y / D i r e c t o r y System." J o u r n a l  o f Systems Management, 24 ( D e c , 1973), 12-9. Mendes, K a t h l e e n S. " S t r u c t u r e d Sytems A n a l y s i s r A T e c h n i q u e t o D e f i n e B u s i n e s s R e q u i r e m e n t s . " S l o a n Management Review, 21, No. 4 ( 1 9 8 0 ) , 51-63. N o l a n , R i c h a r d L. "Computer D a t a B a s e s : T h e F u t u r e i s Now." H a r v a r d B u s i n e s s Review, 51, No. 5 ( 1 9 7 3 ) , 98-114. Power, G e r a l d L. " D e v e l o p i n g Your D i s t r i b u t e d D a t a B a s e . " C o m p u t e r w o r l d , 15 ( J a n . 12, 1981), In D e p t h 33-8. S c r e i b e r , F a b i o A., and G. M a r t e l l a . " C r e a t i n g a C o n c e p t u a l Model of a D a t a D i c t i o n a r y f o r D i s t r i b u t e d D a t a B a s e s . " D a t a Base, 11, No.1 ( 1 9 7 9 ) , 12-8. S h u s s e l , G e o r g e . "The R o l e of t h e D a t a D i c t i o n a r y . " D a t a m a t i o n , 23, No. 6 ( 1 9 7 7 ) , 129-42. S e c r e s t , R i c h a r d D. "The D a t a A d m i n i s t r a t o r . " In The  I n f o r m a t i o n Sytems Handbook. Ed. F.W. M c F a r l a n & R.L. Nowlan. Homewood, I l l i n o i s : Dow J o n e s - I r w i n , 1975, pp.647-57. U r o w c z i k , P.P. "Data D i c t i o n a r y / D i r e c t o r i e s . " IBM Systems  J o u r n a l , 12 ( 1 9 7 3 ) , 332-50. W a t e r s , S . J . "Towards C o m p r e h e n s i v e S p e c i f i c a t i o n s . " Computer J o u r n a l , 22 ( A u g u s t , 1979), 195-99. 1 44 Sharman, G.C.H. and N. W i n t e r b o t t o m . "The D a t a D i c t i o n a r y F a c i l i t i e s o f NDB." P r o c e e d i n g s o f t h e F o u r t h I n t e r n a t i o n a l C o n f e r e n c e on V e r y L a r g e D a t a B a s e s . September, 1978, pp.186-97. Z i e h e , T h e o d o r e W. "What Management S h o u l d Know About IRM." C o m p u t e r w o r l d , 14 ( O c t . 13, 1980), In D e p t h 9-14. 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0095447/manifest

Comment

Related Items