Data Dictionary is defined to be the set of all data attributes, which describe data objects in terms of their intrinsic attributes, such as name, type, size, format and definition. It is recognized as the data base for the Information Resource Management, to facilitate understanding and communication about the relationship between systems applications and systems data usage and to help assist in achieving data independence by permitting systems applications to access data knowledge of the location or storage characteristics of the data in the system. A research and development effort to use Ada has produced a data dictionary with data base design capabilities. This project supports data specification and analysis and offers a choice of the relational, network, and hierarchical model for logical data based design. It provides a highly integrated set of analysis and design transformation tools which range from templates for data element definition, spreadsheet for defining functional dependencies, normalization, to logical design generator

Kwok, Teresa Ting-Yin

Lekkos, Anthony A.

English

NASA Technical Reports Server

Rdes ign:  A Data D i c t i o n a r y  w i t h  Re la t iQna l  Database Des ign  
C a p a b i l i t i e s  i n  Ada 
Anthony A. Lekkos 
Teresa Ting-Yin Kwok 
1 
U n i v e r s i t y  of  Hous ton ,  Clear  L a k e  
1. I n t r o d u c t i o n  
Data D i c t i o n a r y  is d e f i n e d  t o  be t h e  set of a l l  d a t a  
a t t r i b u t e s ,  which describe d a t a  o b j e c t s  i n  terms of  t h e i r  
i n t r i n s i c  a t t r i b u t e s ,  s u c h  a s  name,  t y p e ,  s i z e ,  format and  
d e f i n i t i o n .  I t  is r e c o g n i z e d  as  t h e  da tabase  f o r  t h e  
I n f o r m a t i o n  Resource  Management -- t o  f a c i l i t a t e  
u n d e r s t a n d i n g  and  communicat ion a b o u t  t h e  r e l a t i o n s h i p  
be tween system a p p l i c a t i o n s  and s y s t e m  d a t a  u s a g e  and t o  
a s s i s t  i n  a c h i e v i n g  d a t a  independence  by p e r m i t t i n g  s y s t e m  
a p p l i c a t i o n s  t o  access d a t a  w i t h o u t  knowledge o f  t h e  
l o c a t i o n  or s t o r a g e  cha rac t e r i s t i c s  o f  t h e  d a t a  i n  t h e  
s y s t e m  [ A l l e n 8 2 ] .  
T h e  f o l l o w i n g  a re  c o n s i d e r e d  t o  be its p r i m a r y  
o b j e c t i v e s  : - 
1. To a c h i e v e  c o n t r o l  o f  t h e  d a t a  r e s o u r c e ,  by  
p r o v i d i n g  a n  i n v e n t o r y  o f  t h a t  r e s o u r c e .  To 
e n f o r c e  s t a n d a r d s  and v a l i d a t i o n .  
2 .  To c o n t r o l  t h e  c o s t s  of  d e v e l o p i n g  and m a i n -  
t a i n i n g  a p p l i c a t i o n s .  
3 .  To p r o v i d e  f o r  i ndependence  o f  m e t a d a t a  
across comput ing  e n v i r o n m e n t s ,  improving  
r e s i l i e n c y  t o  t h e  e f f e c t s  o f  hardware and 
s o f t w a r e  c h a n g e s  [ A l l e n 8 2 ] .  
Much of t h e  i m p o r t a n c e  o f  a d a t a  d i c t i o n a r y  h a s  been  
r e c o g n i z e d ,  y e t ,  l i t t l e  o f  i t  h a s  been  u t i l i z e d  t o  s u p p o r t  
a n  a u t o m a t e d  database d e s i g n  . 
* 
Ada is a r e g i s t e r e d  t r ademark  o f  t h e  U.S Government- Ada 
J o i n t  Program O f f i c e .  
S u p p o r t e d  by NASA/JSC-UHCL Ada-Beta s i t e  Con t rac  t. 
F.4.5.1 
https://ntrs.nasa.gov/search.jsp?R=19890006997 2020-03-20T03:41:32+00:00Z
A research and development effort to use ADA at UHCL 
has produced a data dictionary with database design 
capabilities. This project supports data specification and 
analysis and offers a choice of the relational, network, and 
hierarchical model for logical database design. It provides 
a highly-integrated set of analysis and design 
transformation tools which range from templates for data 
element definition or modification, spreadsheet for defining 
functional dependencies, normalization, to logical design 
generator. 
2 .  The Data Dictionary with Database DeSiqn Capabilities 
2.1 The Data Dictionary 
The structure for the data dictionary is essentially 
relational in nature with the data element definition 
normalized to third normal form, while the related projects 
are kept in another relation. Further, the dictionary is 
furnished with the following facilities:- 
Define -- 
creates a new data element entry in the data 
dictionary. A template is used to enter the 
data element name, type, size, range, 
description, validation rules, picture, 
intensity, display attribute, should the 
element type be enumeration, the enumeration 
list could also be entered. 
Modify -- 
changes any data element specification 
created with "Define". If the data element 
name is changed, it creates a new data 
element under this new name -- essentially, 
it performs a "Copy" function under this 
circumstance. Again, a template is used for 
all field entries. 
Search -- 
retrieves data element specifications from 
the data dictionary and displays them on 
screen, This differs from "Report" in that 
only data element names are displayed. A 
global search could be done by entering an 
II * II . A list of names will be displayed on 
screen one page at a time, 
F.4.5.2 
P u r g e  -- 
removes a d a t a  e l e m e n t  from 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  e l e m e n t  is used  o n l y  
i n  t h e  current  p r o j e c t .  The e l e m e n t  is n o t  
purged i f  i t  is used by o t h e r  p r o j e c t s .  
T r a n s f e r  -- 
impor t s  d a t a  e l e m e n t  d e f i n i t i o n s  from an 
e x t e r n a l  t e x t  f i l e  o r  e x p o r t s  d a t a  e l e m e n t  
d e f i n i t i o n s  t o  an e x t e r n a l  t e x t  f i l e .  All of 
t h e  e l e m e n t s  cou ld  be imported o r  e x p o r t e d  
a l l  a t  once ,  o r  they  c o u l d  be imported o r  
e x p o r t e d  i n d i v i d u a l l y ,  o r  t hey  cou ld  be 
imported o r  expor t ed  a c c o r d i n g  t o  p r o j e c t s .  
Repor t  -- 
l ists  i n  d e t a i l  t h e  d a t a  e l e m e n t  d e f i n i t i o n  
f o r  a s i n g l e  d a t a  e l e m e n t  o r  a series of 
d a t a  e l e m e n t s .  The l i s t i n g  c o u l d  go t o  t h e  
t e r m i n a l  o r  t o  t h e  system p r i n t e r .  I f  
t e r m i n a l  is chosen a s  t h e  o u t p u t  d e v i c e ,  t h e  
da t a  e l e m e n t  d e f i n i t i o n  w i l l  be d i s p l a y e d  on 
screen one page a t  a t i m e .  
2.2 F u n c t i o n a l  Dependencies 
Given a p r o j e c t  w i t h  i ts own set  of d a t a  e l e m e n t s ,  one 
can proceed  t o  d e f i n e  f u n c t i o n a l  dependenc ie s  amongst d a t a  
e l e m e n t s .  The f o l l o w i n g  f a c i l i t i e s  a re  provided  :- 
Clear -- 
which c l e a r s  o u t  a l l  p r e v i o u s l y  d e f i n e d  
f u n c t i o n a  dependencies .  
S p r e a d s h e e t  -- 
d a t a  e l e m e n t  names are  d i s p l a y e d  i n  rows and 
columns i n  a s p r e a d s h e e t .  E n t e r i n g  appro-  
p r i a t e  symbols i n  co r re spond ing  p o s i t i o n s  o r  
"cells" w i l l  d e f i n e  f u n c t i o n a l  dependenc ie s  
amongst e l e m e n t s .  Using t h e  t ab  key o r  a r row 
keys ,  one can  move around t h e  cells .  Should 
t h e  a r row go beyond bounds t h e  s p r e a d s h e e t  
w i l l  move one column l e f t / r i g h t  o r  one row 
up/down dependent  on t h e  a r row key h i t  and 
i t s  p o s i t i o n .  One can a l s o  move t h e  
s p r e a d s h e e t  one page a t  a t i m e  by p r e s s i n g  
Func t ion  key 1, 2, 3 o r  4 t o  go up, down, 
l e f t  or r i g h t .  
F.4.5.3 
The following symbols are used to define functional 
dependencies :- 
==> means row element determines column element 
<== means column element determines row element 
K E Y  means element is a key, row element name should 
be the same name as column element 
N/A means not applicable, row element name should be 
the same as column element name where the 
element is not a key 
+=> means concatenation of row elements to identify 
column element 
<=+ means concatenation of column elements to 
identify row element 
To make the spreadsheet even more convenient to use, 
there are a few hidden keys :- 
R = Refresh -- 
the screen is refreshed, in addition 
todisplaying symbols used to define elements 
functional dependencies, the complementary 
symbols are also displayed. 
H = Help -- 
help can be invoked. 
B = Beginning'-- 
spreadsheet moves to the beginning of the 
list of data elements row-wise or column- 
wise. 
E = End -- 
spreadsheet moves to the end of data element 
list row-wise or column-wise. 
F = Find -- 
gets a particular data element which will be 
displayed in the middle of the list row-wise 
or column-wise . 
F.4.5.4 
T = Toggle -- 
Toggles  t h e  symbol, f o r  example,  p r e s s i n g  "TI' 
a t  a p l a c e  where i t  d i s p l a y s  "N/A"  w i l l  
change t h e  symbol t o  " K E Y " .  
To update  t h e  f u n c t i o n a l  dependenc ie s ,  one 
o n l y  needs t o  b l a n k  o u t  t h e  e n t r y ,  en te r  
a p p r o p r i a t e  symbols o r  j u s t  t o g g l e  t h e  
symbols. 
P = P r i n t  -- 
w i l l  p r i n t  o u t  t h e  f u n c t i o n a l  dependenc ie s  t o  
t h e  screen o r  t o  a f i l e .  
2.3 Database  Design Genera tor  
Af t e r  t h e  f u n c t i o n a l  dependenc ie s  a r e  d e f i n e d ,  t h e  
n o r m a l i z a t i o n  t o o l  can be u t i l i z e d  t o  a u t o m a t i c a l l y  
no rma l i ze  t h e  r e l a t i o n s  i n  t h i r d  normal form. Each t a b l e  
s t r u c t u r e  is d i s p l a y e d  and a name should  be g iven .  
A t  t h i s  p o i n t ,  a l l  t h e  t a b l e s  s o  created a re  i n  t h i r d  
normal form. 
For a p p l i c a t i o n  o r  implementat ion r e a s o n s ,  one may have 
t o  v i o l a t e  t h e  rules  f o r  n o r m a l i z a t i o n  o r  t o  keep c e r t a i n  
r e l a t i o n s  n o t  i n  t h i r d  normal form. A " m a i n t a i n - t a b l e "  
f a c i l i t y  is p rov ided  s o  t h a t  a d a t a b a s e  d e s i g n e r  can  d e f i n e  
h i s  own t a b l e  w i t h  i t s  own se t  of keys and a t t r i b u t e s .  
Moreover, he c a n  rename a t a b l e ,  d e l e t e  a t ab le ,  d e l e t e  
c e r t a i n  keys  o r  a t t r i b u t e s  i n  a t ab l e  o r  add ce r t a in  keys 
o r  a t t r i b u t e s  i n  a t ab le .  T h e  system w i l l  n o t  r e -no rma l i ze  
t h e s e  t a b l e s .  T h e r e  is one c o n s t r a i n t ,  however, t h e  keys 
and/or a t t r i b u t e s  had t o  be d e f i n e d  i n  d a t a  d i c t i o n a r y .  
Again a s p r e a d s h e e t  is employed t o  d e f i n e  t h e  
r e l a t i o n s h i p s  amongst r e l a t i o n s ,  be i t  one-to-one, one- to-  
many, many-to-many o r  n o - r e l a t i o n s .  
A refresh f u n c t i o n  w i l l  n o t  be a p p l i c a b l e  i n  t h i s  c a s e  
as t h e  r e l a t i o n s h i p  be tween t h e  row r e l a t i o n  and t h e  column 
r e l a t i o n  may n o t  be r e c i p r o c a l .  
A p a r e n t - c h i l d  g raph  cou ld  be g e n e r a t e d  a f t e r  t h e  
r e l a t i o n s h i p s  are  d e f i n e d .  The g raph  cou ld  be p r i n t e d  o u t  
t o  t h e  sys tem p r i n t e r  o r  t o  t h e  screen. 
The c o n c e p t u a l  schema is t h e n  g e n e r a t e d  and o u t p u t  goes  
t o  t h e  screen and a t e x t  f i l e  so t h a t  t h e  d e s i g n e r  can v i e w  
i t  and make m o d i f i c a t i o n s  i f  n e c e s s a r y .  S i n c e  t h e  d a t a  
e l e m e n t s  used a re  governed by t h e  da t a  d i c t i o n a r y ,  
c o n s i s t e n c y ,  i n t e g r i t y  and v a l i d i t y  can be ach ieved  e a s i l y .  
F.4.5.5 
FOllOWing is a SQL-type l o g i c a l  d e s i g n  i n t e r f a c e  so 
g e n e r a t e d  :- 
R e m  
R e m  SQL/DS Database D e s i g n  I d e n t i f i c a t i o n  S e c t i o n  
R e m  
R e m  Appl ica t ion  : DIS 
R e m  
R e m  Date created: 6/6/86 
R e m  
R e m  SQL/DS Database Tables  Create Commands S e c t i o n  
R e m  .................................................... 
Create T a b l e  DEPT 
(DEPT NAME Char  (32) n o t  n u l l ,  
BUDGFT Number ( 7 )  I 
DE PT-MGR C h a r  (32) I 
LOCATION C h a r  (32)) ; 
Create Unique  I n d e x  DEPT - I N D E X  on DEPT (DEPT - NAME) ; 
2 r e a t e  Table  EMPLOYEE 
(EMP NAME C h a r  (32) n o t  n u l l ,  
DEPT NAME C h a r  (32) I 
EMPLZNT DATE C h a r  ( 8 )  , 
POS I TI OK C h a r  (32) 1 
SALARY Number ( 7 ) )  ; 
3 r e a t e  Unique Index  EMPL - I N D E X  on EMPLOYEE (EMP - NAME I 
:rea te Tab le  PROJECT 
(PROJ NAME C h a r  (32) n o t  n u l l ,  
DEPT-NAME C h a r  (32) I 
CHAREE NO Number ( 4 )  8 
COMPL EATE C h a r  ( 8 )  
PROJ - EEADER C h a r  (32)) ; 
:reate Unique I n d e x  PROJ I N D E X  on PROJECT (PROJ NAME);  
:reate T a b l e  EMP - PROJ 
(EMP NAME C h a r  (32) n o t  n u l l ,  
PRO5 NAME C h a r  (32) n o t  n u l l ,  
EMPPROJ-DATE  C h a r  ( 8 ) )  ; 
- - 
CHAREED HRS Number ( 4 )  , 
:reate Unique  Index  EMPPROJ I N D E X  on EMP PROJ - - 
(EMP - NAME, PROJ - NAME) ; 
3. User Interface 
F . 4 . 5 . 6  
Much of t h e  work  f o r  m a i n t a i n i n g  t h e  d a t a  d i c t i o n a r y  is  
done  t h r o u g h  a template, e . g . ,  d e f i n e  and mod i fy ,  user o n l y  
n e e d s  t o  f i l l  i n  t h e  b l a n k s ,  o t h e r  w o r k  l i k e  d e f i n i n g  
f u n c t i o n a l  d e p e n d e n c i e s  and r e l a t i o n s h i p s  amongs t  t a b l e s  is 
done  t h r o u g h  a spreadshee t .  The  w h o l e  s y s t e m  is menu d r i v e n  
w i t h  t h e  f i r s t  two rows of t h e  s c r e e n  ded ica t ed  t o  commands. 
To  go up  t o  t h e  command l i n e ,  o n e  o n l y  n e e d s  t o  press <F2>.  
One c a n  t h e n  u s e  Tab, o r  arrows t o  move a c r o s s  t h e  command 
l i n e .  A < r e t u r n >  selects t h  command. T h e  2 4 t h  row on t h e  
s c r e e n  is d e d i c a t e d  t o  f u n c t i o n  key  e x p l a n a t i o n  w h i l e  t h e  
23 rd  row is  used  f o r  message  l i n e  and  t h e  22nd row is used  
f o r  prompt l i n e .  The  r e s t  of  t h e  s c r e e n  w i l l  be u s e d  f o r  
d i s p l a y  or  f o r  t h e  template.  Help c o u l d  be invoked  
t h r o u g h o u t  t h e  s c r e e n s  . 
R e f e r e n c e s  
[Al l en821  F rank  W. A l l e n ,  Mary E. S. Loomis, Michael V. 
Mannino "The I n t e g r a t e d  D i c t i o n a r y / D i r e c  t o r y  
System" 8 ACM Comp. S u r v e y , l 4 : 2 ,  1982.  
[ G o l d s t e i n 8 5 1  R o b e r t  C. G o l d s t e i n  "Database :Technology and  
Management John  Wiley  and Sons ,  I n c . ,  1985.  
[ C u r t i c e 8 4 1  R.M. C u r t i c e  " I R M A :  An Automated L o g i c a l  Data  
Base Des ign  and  S t r u c t u r e d  A n a l y s i s  T o o l " ,  
I E E E  Database Eng. 7:4 ,  December 1984.  
f R e i n e r 8 6 1  David R e i n e r ,  G r e t c h e n  Brown, Mark F r i e d e l l ,  
e t  a l ,  "A Database D e s i g n e r ' s  Workbench" 
s u b m i t t e d  t o  D i j o n  ER C o n f e r e n c e ,  1986.  
Database Des ign  Tool f o r  t h e  R e l a t i o n a l  Model 
of Data", I E E E  Database Eng. 7 :4 ,  December 
1984.  
[ B J o r n e r s t e d t 8 4 1  A . B j o r n e r s t e d t  and C. H u l t e n  " R E D 1 :  A 
F.4.5.7 


Rdesign: A data dictionary with relational database design capabilities in Ada

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