desirable set of software characteristics for the micro-computer market. Center for ..... features. A machine language sort seemed to be the most common extra.
DATA MANAGEMENT SYSTEMS FOR MICRO-COMPUTERS: A SURVEY by Alan J. Hughes Eileen M. Lynch Edward A. Stohr
October, 1981
Presented at the Conference on Surall Business Systems, Rutgers University, November 6-7, 1980.
Working Paper Series STERN IS-8 1-69
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
I. INTRODUCTION The r a p i d growth of micro-computer
technology i n r e c e n t y e a r s has suddenly
made cheap computing a v a i l a b l e t o s m a l l b u s i n e s s u s e r s and h o b b y i s t s .
The
performance c a p a b i l i t y of micro-computers i s now approaching t h a t of t h e mini-computers
o f a few y e a r s ago.
As was t h e c a s e f o r mini-computers,
we can
e x p e c t t h a t micro-computer m a n u f a c t u r e r s and s o f t w a r e vendors w i l l o f f e r i n c r e a s i n g l y s o p h i s t i c a t e d u s e r s u p p o r t and s o f t w a r e packages.
Operating
systems a r e now becoming g e n e r a l l y a v a i l a b l e t o g e t h e r w i t h a v a r i e t y of packages f o r common b u s i n e s s a p p l i c a t i o n s .
Among t h e s e packages a r e many ~ i l e
Management Systems (FMS'S) and s e v e r a l Data Base Management Systems (DBMS's). A n FMS, p r o v i d e s f a c i l i t i e s f o r f i l e c r e a t i o n , maintenance,
r e p o r t generation.
r e t r i e v a l and
Usually a number of independent f i l e s a r e c r e a t e d each
supporting a s i n g l e application.
Some FMS's can s i m u l t a n e o u s l y a c c e s s s e v e r a l
f i l e s e i t h e r f o r r e t r i e v a l o r f o r update ( e g . m a s t e r and t r a n s a c t i o n f i l e s ) .
A
DBMS on t h e o t h e r hand c r e a t e s and manages a non-redundant d a t a s t r u c t u r e i n which v a r i o u s d a t a 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 and which can s u p p o r t a number of d i f f e r e n t a p p l i c a t i o n s . T h i s p a p e r s u r v e y s t h e emerging f i e l d of d a t a management s o f t w a r e f o r micro-computer
systems.
O u r o b j e c t i v e s a r e t o p r o v i d e a guide t o t h e a v a i l a b l e
s o f t w a r e and t o survey a c t u a l and p o t e n t i a l u s e r s and a p p l i c a t i o n s .
For
r e f e r e n c e , e x c e l l e n t s u r v e y s of d a t a base management systems f o r maxi- and mini- computers a r e c o n t a i n e d i n [ 11 and [ 5 ] r e s p e c t i v e l y . The market f o r g e n e r a l purpose d a t a management s o f t w a r e i s d i s c u s s e d b r i e f l y i n S e c t i o n 2. unsatisfied.
The p o t e n t i a l i s l a r g e b u t a s y e t almost completely
Some of t h e problems i n v o l v e d i n d e v e l o p i n g s o f t w a r e f o r s m a l l
b u s i n e s s u s e r s a r e d i s c u s s e d i n S e c t i o n 3.
This section a l s o describes a
d e s i r a b l e s e t of s o f t w a r e c h a r a c t e r i s t i c s f o r t h e micro-computer market.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
The r e s u l t s of a survey of micro-computer manufacturers and s o f t w a r e v e n d o r s a r e d e s c r i b e d i n S e c t i o n 4.
A l i s t of t h e systems and vendors i s g i v e n
i n Appendix I and a summary of t h e vendor survey q u e s t i o n n a i r e i n Appendix 11. A l l o f t h e systems a r e a v a i l a b l e f o r machines with l e s s t h a n o r e q u a l t o 64K
memory and 8 - b i t microprocessor chips.
Some a r e a v a i l a b l e f o r a wide v a r i e t y
of machines and o p e r a t i n g systems; some vendors a r e p l a n n i n g v e r s i o n f o r t h e new 1 6 - b i t micorprocessors.
The s o f t w a r e f e a t u r e s o f f e r e d vary widely
i n c l u d i n g s i m p l e s i n g l e f i l e r e t r i e v a l system, m u l t i - f i l e r e t r i e v a l s y s t a - 5 , multi-file
FMSfs designed t o a s s i s t i n t r a d i t i o n a l b u s i n e s s f u n c t i o n s such a s
p a y r o l l and i n v e n t o r y c o n t r o l and f u l l - f l e d g e d DBM's.
S u r p r i s i n g l y , i n terms
o f t h e f e a t u r e s provided by t h i s s o f t w a r e w e f i n d some systems which a r e approaching t h e s o p h i s t i c a t i o n of t h e i r maxi-computer
counterparts*
The packages i n t h e sample were chosen t o be t y p i c a l examples c o v e r i n g a r a n g e of d i f f e r e n t system t y p e s .
The l i s t i s n o t e x h a u s t i v e .
Nor does
i n c l u s i o n of a system i n t h e l i s t imply t h a t i t i s t o be p r e f e r r e d t o a n o t h e r n o t on t h e l i s t .
O u r o b j e c t i v e i s t o p r o v i d e an overview of t h e k i n d s o f
s o f t w a r e a v a i l a b l e , n o t t o recommend any p a r t i c u l a r package. be f o o l i s h t o do so.
Indeed it would
F i r s t , because t h e c o r r e c t c h o i c e of a package depends
h e a v i l y on t h e i n t e n d e d a p p l i c a t i o n and secondly because new systems and upgrades of e x i s t i n g systems a r e b e i n g c o n t i n u a l l y i n t r o d u c e d In addition t o t h e 'supply-sidef
i t i s important t o consider t h e e x i s t i n g
and p o t e n t i a l u s e s of d a t a management t e c h n o l o g y . s u r v e y of DBMS u s e r s a r e r e p o r t e d i n S e c t i o n 5.
The r e s u l t s of a s m a l l The u s e r survey q u e s t i o n n a i r e
i s a l s o summarized i n Appendix 11.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
2. MARKETS FOR MICROCOMPUTER DATA MANAGEMENT SOFTWARE The m a j o r markets f o r d a t a management s o f t w a r e a r e :
o Small b u s i n e s s , p r o f e s s i o n a l and n o n - p r o f i t o r g a n i z a t i o n s
o Medium-large b u s i n e s s e s o Small b u s i n e s s s o f t w a r e d e v e l o p e r s o P e r s o n a l and home use The f i r s t c a t e g o r y l i s t e d above i s l i k e l y to be t h e most i m p o r t a n t i n t h e s h o r t t o i n t e r m e d i a t e term.
I f we c o n s i d e r a s m a l l b u s i n e s s a s one w i t h l e s s
t h a n $4 m i l l i o n s a l e s t h e r e i s a p o t e n t i a l market of perhaps one m i l l i o n companies.
However it w i l l be some t i m e b e f o r e t h e u t i l i t y of computers f o r
many companies ( e s p e c i a l l y t h o s e w i t h s a l e s l e s s t h a n $ 2 m i l l i o n ) becomes self-evident.
Two r e l a t e d a p p l i c a t i o n s
- word-processing
and m a i l i n g have
a l r e a d y e s t a b l i s h e d themselves a s p r a c t i c a l and u s e f u l f o r many m a l l b u s i n e s s e s with micro-computers
a t t h e s m a l l e r end of t h e range.
b u s i n e s s a p p l i c a t i o n s w i l l be next.
More g e n e r a l
These range from simple f i l e r e t r i e v a l '
a p p l i c a t i o n s (eg. maintaining a l i s t of customers) t o t r a d i t i o n a l b u s i n e s s a p p l i c a t i o n s such a s i n v e n t o r y c o n t r o l .
The s p e c i a l problems i n v o l v e d i n
d e v e l o p i n g s o f t w a r e f o r s m a l l b u s i n e s s w i l l be d i s c u s s e d i n s e c t i o n 3 . A number of u s e r s i n o u r survey were d e v e l o p i n g d e c e n t r a l i z e d s p e c i a l
purpose systems w i t h i n l a r g e o r g a n i z a t i o n s .
These u s e r s were more
s o p h i s t i c a t e d and were p r e p a r e d t o spend time l e a r n i n g t h e d a t a management package and developing t h e i r a p p l i c a t i o n s .
They purchased t h e more p o w e r f u l
f i l e management and d a t a base management systems. A number of s o f t w a r e d e v e l o p e r s have a l s o purchased t h e more s o p h i s t i c a t e d
f i l e management and d a t a base management systems and a r e u s i n g them a s b u i l d i n g b l o c k s f o r developing b u s i n e s s a p p l i c a t i o n packages f o r r e s a l e t o end u s e r s . F i n a l l y t h e r e i s a market f o r f i l e managemen:
systems f o r p e r s o n a l u s e .
~t t h i s s t a g e it i s n o t c l e a r how q u i c k l y t h i s market w i l l d e v e l o p beyond a
r e l a t i v e l y few h o b b y i s t u s e r s .
The volume of r e t r i e v a l t r a n s a c t i o n s f o r
t y p i c a l home a p p l i c a t i o n s such a s r e c i p e s and l i s t s of p e r s o n a l f r i e n d s does n o t m e r i t t h e e x t r a overhead of computerized methods when compared w i t h manual systems.
The s i t u a t i o n may change a s i n f o r m a t i o n u t i l i t i e s l i n k e d t o home
t e l e v i s i o n s e t s become widespread. t o tap-off
I n t h i s c a s e consumers may g e t t h e a b i l i t y
l i m i t e d f i l e s of i n f o r m a t i o n f o r s p e c i a l p r o c e s s i n g i n t h e i r own
'distributed'
d a t a bases.
3. DESIRABLE PRODUCT CHARACTERISTICS
Development of micro-computer
software f o r small business u s e r s p r e s e n t s a
s p e c i a l s e t o f problems and c h a l l e n g e s never b e f o r e f a c e d by t h e s o f t w a r e industry.
I n t h e f i r s t p l a c e machines i n a s u i t a b l e p r i c e range ( s a y $5,000 t o
$15,000) have s e v e r e c o n t r a i n t s i n t e r m s of memory c a p a c i t y , speed and o p e r a t i n g system c a p a b i l i t y .
Secondly, t h e systems must be s u i t a b l e f o r
o p e r a t i o n by n a i v e u s e r s w i t h n e i t h e r t h e t i m e nor t h e i n c l i n a t i o n t o i n v e s t i n s u p p o r t i n g a computerized system.
L a r g e r companies always have been a b l e to
s p e c i a l i z e t h e i r work f o r c e s f o r such t a s k s a s d a t a e n t r y and v a l i d a t i o n , system o p e r a t i o n and f i l e maintenance.
Small companies can n o t a f f o r d t h i s .
few employees must perform a l l b u s i n e s s f u n c t i o n s .
A
Time s p e n t i n s u p p o r t i n g
f u n c t i o n s t h a t a r e not d i r e c t l y revenue producing must be reduced t o a minimum. F i g u r e 1 summarizes t h e s e and o t h e r c h a r a c t e r i s t i c s of m a l l b u s i n e s s systems.
The arrows i n d i c a t e t h e major s o f t w a r e i m p l i c a t i o n s .
Our s u r v e y o f
a v a i l a b l e d a t a management systems shows t h a t d e s i g n e r s have been s e n s i t i v e t o some of t h e s e needs.
However, no c u r r e n t system comes c l o s e t o s a t i s f y i n g a l l
o f them.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
SMALL BUSINESS
IMPLICATIONS FOR SOFTWARE
CHARACTERISTICS
-
o PERSONAL
GOOD 'HUTlLAN ENGINEERING'
L (,
o INDIVIDUALS PERFORM
RESPONSIVE SYSTEMS
MANY FUNCTIONS
o UNPREDICTABLE WORK
ON-LINE UPDATE (DEAL WITH ONE TRANSACTION AT A TIME)
ENVIRONMENT o LITTLE UNDERSTANDING
,L
o FILE MAINTENANCE
OF COMPUTERS
FUNCTIONS TRANSPAR?3T
o CAN NOT AFFORD TO
'TURNKEY' SYSTEMS
PAY FOR PROGWNMING PORTABLE SYSTEMS o UNDERGO GROWTH
FLEXIBLE SYSTEMS -CAN RESTRUCTURE
AND CHANGE o LITTLE UNDERSTANDING
F &
o DESIGNERS OF APPLICATIONS
OF BUSINESS SYSTElS
MUST UNDERSTAND THE BUSINESS
FIGURE 1 DESIRABLE SOFTWARE ATTRIBUTES
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
~ o o dHuman Engineerinq W e have a l r e a d y mentioned t h e need f o r u s e r - f r i e n d l y
systems.
Section 4
w i l l expand on some of t h e f e a t u r e s provided by c u r r e n t software t o meet t h i s requirement. Responsive Systems Small b u s i n e s s systems a r e c h a r a c t e r i z e d by an u p r e d i c t a b l e w r k environment and a r e d r i v e n by randomly o c c u r i n g e v e n t s .
Because it i s n o t
p o s s i b l e t o s p e c i a l i z e a p l o y e e work f u n c t i o n s t h e r e i s no p o s s i b i l i t y of b u f f e r i n g t h e system from i t s environment. Systems be ' r e s p o n s i v e '
This i m p l i e s a requirement t h a t
i n t h e sense t h a t t h e o p e r a t o r can q u i c k l y change t h e
mode of o p e r a t i o n without e x t e n s i v e f i l e management o p e r a t i o n s and without compromising system i n t e g r i t y .
The a b i l i t y t o move q u i c k l y from t h e p r o c e s s i n g
o f one t r a n s a c t i o n type t o a n o t h e r o r t o a d i f f e r e n t f i l e t y p e i s a d e s i r a b l e attribute. On-Line Update One a s p e c t of a responsive system i s t o allow o n - l i n e update of f i l e s . Most of t h e f i l e management systems a l l o w t h i s .
Some systems allow t h e o n - l i n e
u s e r t o batch update r e q u e s t s f o r g r e a t e r e f f i c i e n c y ; some a l l o w a given update t o be performed on a s e l e c t e d group of r e c o r s s . t h e system i s u s u a l l y one record at-a-time.
However, t h e primary a c c e s s t o
This c o n t r a s t s with the master
f i l e / t r a n s a c t i o n f i l e mode of p r o c e s s i n g which predominates i n many l a r g e r businesses.
The one t r a n s a c t i o n at-a-time
mode f i t s w i t h o t h e r c h a r a c t e r i s t i c s
of a small b u s i n e s s and i s s u i t a b l e f o r a s m a l l volume of heterogeneous transactions.
A s volume grows however,
can y i e l d g r e a t economies.
s p e c i a l i z a t i o n of d a t a e n t r y f u n c t i o n s
Some of t h e f i l e management systems a l r e a d y on t h e
market a n t i c i p a t e t h i s r e q u i r e k e n t .
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
F i l e Maintenance F u c t i o n s T r a n s p a r e n t S i n c e b u s i n e s s u s e r s u s u a l l y have l i t t l e understanding of computers,
file
maintenance o p e r a t i o n s such a s backup and r e c o v e r y from system f a i l u r e a r e l i l e l y t o be troublesome a r e a s . handled a u t o m a t i c a l l y .
A s f a r as p o s s i b l e t h e s e f u n c t i o n s s h o u l d be
T h i s i s an a r e a of weakness f o r many e x i s t i n g systems*
U n l e s s t h e u s e r can a f f o r d a hard d i s k system t h e p h y s i c a l h a n d l i n g of d i s k e t t e s i n and o u t of d i f f e r e n t d r i v e s i s unavoidable.
However t h e u s e r must
a l s o c r e a t e and manage back-up f i l e s i n an organized fashion.
Only a few of
t h e systems surveyed have a b u i l t - i n f u n c t i o n t o back-up a f i l e .
AS a
consequence t h e u s e r must understand t h e o p e r a t i n g system i n s u f f i c i e n t d e t a i l t o p e r f o m t h i s functionTurnkey Systems S i n c e s m a l l b u s i n e s s e s u s u a l l y can n o t a f f o r d t o i n v e s t i n programming it
i s o b v i o u s t h a t t h e y need t o p u r c h a s e ' o f f - t h e
s h e l f ' computerized s o l u t i o n s t o
t h e i r b u s i n e s s problems. Where t h e a p p l i c a t i o n s a r e c l e a r and simple a s i n m a i l i n g l a b e l s and m a i n t a i n i n g simple l i s t s of i n f o r m a t i o n t h i s can be done e a s i l y enough. S e v e r a l f i l e management systems i n c l u d e q u i t e e l e g a n t form d e s i g n f a c i l i t i e s tn add an e x t r a dimension of g e n e r a l i t y .
Some a r e i n t e g r a t e d with w o r d - ~ r o c e s s i n g
and m a i l i n g packages o f f e r e d by t h e same vendor.
However, more complex
b u s i n e s s a p p l i c a t i o n s such a s p a y r o l l , i n v e n t o r y c o n t r o l and g e n e r a l l e d g e r a r e h a r d e r t o provide a s ' t u r n k e y '
systems because of d i f f e r e n c e s i n b u s i n e s s
requirements* Portability The a b i l i t y t o t r a n s p o r t programs from one computer system t o a n o t h e r i s i m p o r t a n t on both t h e supply and demand s i d e s of t h e s o f t w a r e market.
For
s u p p l i e r s it g i v e s a broader market and makes g r e a t e r investment i n development worthwhile.
For t h e m a l l businessman it r e d u c e s t h e r i s k of s o f t w a r e
investment.
There can be l i t t l e doubt t h a t t h e widespread u s e o f 280 and 8080
c h i p t e c h n o l o g y and t h e CP/M o p e r a t i n g system h a s c o n t r i b u t e d g r e a t l y t o t h e growth o f t h e micro-computer
software industry.
Many s o f t w a r e v e n d o r s a r e
i n c r e a s i n g t h e i r m a r k e t s by r e l e a s i n g v e r s i o n s c o m p a t i b l e w i t h more t h a n o n e computer system. F l e x i b l e Systems The need f o r systems which c a n e n d u r e change and growth i s a t l e a s t a s g r e a t a s i n l a r g e systems.
With d a t a management systems t h i s t r a n s l a t e s i n t o
a n a b i l i t y to change f i l e d e f i n i t i o n s and d a t a r e l a t i o n s h i p s .
Very few of t h e
f i l e management systems a l l o w new f i e l d s t o be added t o an e x i s t i n g r e c o r d definition.
Some of t h e systems r e q u i r e t h a t i n d e x e s be r e b u i l t a f t e r t h e
a d d i t i o n of a record t o a f i l e . 'restructuring' systems.
A t t h e o t h e r extreme a n add-on package o f
r o u t i n e s can be p u r c h a s e d f o r one of t h e d a t a b a s e management
.
T h i s a l l o w s a complete r e d e f i n i t i o n o f b o t h r e c o r d s and r e c o r d
i n t e r r e l a t i o n s h i p s under p r o g r a n c o n t r o l . Good B u s i n e s s Systems Many s m a l l companies do n o t have a good u n d e r s t a n d i n g of e i t h e r manual o r c o m p u t e r i z e d b u s i n e s s systems. designers
-
T h i s p l a c e s a n a d d i t i o n a l burden on s o f t w a r e
they must thoroughly understand t h e b u s i n e s s requirements.
E x c e p t i o n c o n d i t i o n s must be a n t i c i p a t e d and a n a u d i t t r a i l p r o v i d e d . m u s t be p r o t e c t e d from e r r o r s of o m i s s i o n and commission. d i s c o v e r e d t h e y must be e a s y t o c o r r e c t .
The u s e r
When e r r o r s a r e
I d e a l l y , a s t h e i n d u s t r y matures
a p p l i c a t i o n systems w i l l be d e s i g n e d by teams c o n s i s t i n g of b o t h b u s i n e s s and systems s p e c i a l i s t s .
Well d e s i g n e d e f f i c i e n t s o f t w a r e i n a narrow s e n s e i s a
n e c e s a r y b u t by no nieans s u f f i c i e n t p r e q u i s i t e f o r s u c c e s s .
The s o f t w a r e
s h o u l d perform t h e c o r r e c t mix pf b u s i n e s s f u n c t i o n s .
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
4.
SURVEY OF AVAILABLE DATA MANAGEMENT SOFTWARE
4.1
C l a s s i f i c a t i o n Scheme The d a t a management systems examined i n t h i s study a r e l i s t e d i n T a b l e 1.
They can be c l a s s i f i e d i n t o a number of d i s t i n c t t y p e s :
1.
2.
F i l e Management Systems
1.1
F i l e Access Methods (FAM)
1.2
S e l f - c o n t a i n e d F i l e Management Systems (FMS)
1.3
A p p l i c a t i o n Developments Systems (ADS)
Data Base Management Systems ( DBMS)
A s i l l u s t r a t e d i n F i g u r e 2 t h e a c c e s s p a t h s through which u s e r s i n t e r a c t
w i t h t h e i r d a t a form t h e major b a s i s f o r t h e above c l a s s i f i c a t i o n . These a c c e s s p a t h s c o n t a i n t h e l o g i c o f t h e u s e r a p p l i c a t i o n w i t h regtird t o some o r a l l of t h e following:
- Data i t e m (SD) - FD p l u s
F i l e D e s c r i p t i o n (FD)
and r e c o r d d e f i n i t i o n s
Schema D e s c r i p t i o n
complex d a t a r e l a t i o n s h i p s
Loading Data (LD) Update (UP)
-
-
adding d a t a t o c r e a t e a f i l e
changing d a t a v a l u e s ; a d d i t i o n s ; d e l e t i o n s
Information R e t r i e v a l ( Z R ) Report Generation ( R G ) Job P r o c e s s i n g (JP)
-
-
answering q u e r i e s from a t e r m i n a l
f o r m a t t e d reports; s p e c i a l forms
- processing
and computation i n v o l v i n g m u l t i p l e
f i l e s and a number of job s t e p s Roughly speaking t h e c l a s s i f i c a t i o n i n d i c a t e s a t r a d e - o f f
between t h e e a s e of
u s e and t h e f u n c t i o n a l g e n e r a l i t y and f l e x i b i l i t y o f t h e s o f t w a r e package. Users a r e r e l i e v e d of complex and o n e r o u s t a s k s when t h e l o g i c a l f u n c t i o n s l i s t e d above a r e c a r r i e d - o u t by t h e s o f t w a r e package r a t h e r t h a n by u s e r - w r i t t e n programs i n a h i g h - l e v e l
languaqe such a s BASIC.
However, u n l e s s
t h e s o f t w a r e package i s p a r t i c u l a r l y powerful t h e a b i l i t y of u s e r s t o m a n i p u l a t e and perform c a l c u l a t i o n s on t h e i r d a t a may be r e s t r i c ' Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
TABLE 1 C&ARACTERXSTICSOF DATA V.'AGFXhT SYSTMS OPERATING SOLXCE SYSTM LAh'GL'AG!!
SYSTEll TYPE
NO. OF US=
CP/H
CBASlC 2
MS
7 50
$250
CP/H
FORTRAN + ASSOiBLY
lJlS
100
$395
24K
TRSWS
BASIC
FXS
1000
$100
280 Kicro
48K
CPiM CWS
280 ASSPfBLY
DENS
60
$695
280 Micro
56K
CP/X CDOS
280 ASSEKBLY
DBXS
15
$5000
Jan. 1978
CBOKEMCO DBMS
CROEEMCO SISTE3 I1 OR 111
64K
CWS
BASIC
FMS
2000
$298
1979
DBHASTFR
APPLE I1
48K
WS 3.3
BASIC+ ASSmBLY
FES
600
$189
Nov. 1980
CP/H, CDOS , HP/M
go80 ASSPZBLY
ADS
200
$750
Oct. 1979
'c'
MS
5 00
$499
Jun.
BASIC
WS
100
$99.95
O c t . 1980
-
REqUIRED CPUSIZE
SYSTM
HARDWARE
ANALPST
280,8080 Xicro
5 2K
280,8080
6 8K
CCA
APPLE 11
DATA M&YAGER
TRS-80 11
CONDOR SERIES ZO/DBMS-I
1
INFO HANAGEB
NORTE STAR BORIZOX
DATE RELEASED Aug. 1979
W/H
56K
(INTEGRAL) As? 2.1.1 TRSWS, BEUIX)S,
+
nos
ASSMGLY
1980
tDBS
280, 8080, 6502 Wicro
64K
CP/M NORTH S%Y TXSDOS
ASSEEBLY
DBXS
300
$900
Nov. 1979
KICRO B+
280, 8080 Micro
N/A
CP/M
ASSLXBLY
F M
100
$260
Sep. 1979
MXCROSEEI)
280 Kicro CP/M
64K
CP/M
FORTRAN
DBFS
H/A
$900
1979
BASIC
FPS
1000
$300
Jun. 1978
CBASIC
ADS
U/A
$795
Nov. 1980
FnS
N/A
$179
1980
+
AsSrnLY '
0s-DMS 'Nucleus'
OSI Challenger I1 o r 111
56K
OS-65U
PRISX/ ADS
280, 8080, 8085 Micro
48R
CP/M
PROFILE
TRS-80 11
32K
~
SELECTOR 111
280,8080, 8085 Micro
46K
CP/M
CBASIC
rr3
1200
$345
Apr. 1979
SELECTOK
280, 6080, 8085 Kicro
52K
CP/M
CBASIC
ADS
150
$550
Sep. 1980
16K
APPLEDCS CBMDOS
ASSPrBLY
'-'AM
500
$175
llov. 1979
W
,
S N/A
IX
N
SUPElCKRAH APPLE X I , COMMODORE PET
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
PACKAGE
U)
APPLICATION
-
-
-
SEW-
OPEPATIN5
CONUDieD
SISrD(
TW
S T s m SYsm
-
t
OPERATIJG
DATA FILES JOB NEtiUS REPnRT DEFMITIONS
FILE DEFIhITION \ /---I REPCRT
i
]F&. M I A BASE
-.
Figure 2
ACCESS PATHS FOR CLASSES OF DATA MANAGEMENT SYSTEM
F i l e a c c e s s methods ( F i g u r e 2 a ) p r o v i d e e f f i c i e n t multi-key a c c e s s from a h o s t language program t o t h e d a t a f i l e s .
However, t h e l o g i c f o r a l l of t h e
above f u n c t i o n s must be coded w i t h i n t h e c a l l i n g programs. The S e l f Contained FMS's a r e f u r t h e r c a t e g o r i z e d i n F i g u r e 2 a c c o r d i n g t o t o whether t h e y a r e t o t a l l y o r p a r t i a l l y s e l f - c o n t a i n e d .
A s o f t w a r e package i s
s e l f - c o n t a i n e d i f it p r o v i d e s t h e complete i n t e r f a c e between a u s e r a p p l i c a t i o n and i t s d a t a base.
Thus a l l of t h e f u n c t i o n s t h a t a r e n e c e s s a r y f o r t h e
a p p l i c a t i o n a r e performed u s i n g t h e language, prompting and menu s e l e c t i o n f e a t u r e s of t h e package i t s e l f .
The u s e r does not have t o program i n a " h o s t "
high l e v e l language (such a s BASIC) o r invoke u t i l i t i e s such a s e d i t o r s and s o r t r o u t i n e s t h a t a r e n o t p a r t of t h e package. The t o t a l l y s e l f - c o n t a i n e d FMS's ( F i g u r e 2 b ) p r o v i d e a s i n g l e i n t e r f a c e T h i s a l l o w s them to perform f u n c t i o n s
t a i l o r e d f o r naive u s e r s .
and RG by s p e c i f y i n g t h e i r r e q u i r e m e n t s non-procedurally.
R),
LD, U P ,
IR -
i.ea users specify
what h a s to be done but t h e d e t a i l s of how t h e p r o c e s s i n g i s t o be c a r r i e d - o u t a r e l e f t t o t h e package.
T h i s works w e l l f o r s i m p l e low volume a p p l i c a t i o n s .
However, e x i s t i n g non-procedural
i n t e r f a c e s g e n e r a l l y can n o t cope w i t h t h e
complex sequence of p r o c e s s i n g needed t o u p d a t e and m a i n t a i n f i l e s f o r more sophisticated applications.
G r e a t e r g e n e r a l i t y i s achieved i n t h e p a r t i a l l y
s e l f - c o n t a i n e d packages ( F i g u r e 2 c ) where t h e FMS f i l e s can a l s o be g e n e r a t e d and/or a c c e s s e d by s e p a r a t e a p p l i c a t i o n programs o r by word-processing and m a i l i n g - l a b e l packages s u p p l i e d by t h e same vendor. An A p p l i c a t i o n Development System ( F i g u r e 2 d ) r e p r e s e n t s a r e l a t i v e l y new
g e n e r a l i z a t i o n of a FMS t o a l l o w t r a n s a c t i o n / m a s t e r a e d i t i o n t o t h e FD, LD, U P ,
f i l e processing.
In
I R and RG i n t e r f a c e s of an FMS, an ADS p r o v i d e s a
J P ( j o b p r o c e s s i n g ) i n t e r f a c e through which u s e r s can d e f i n e a sequence of job
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
s t e p s i n v o l v i n g simple computations, matching and merging and t r a n s f e r of d a t a between t r a n s a c t i o n and m a s t e r f i l e s . A DBMS ( F i g u r e 2 e ) i s d i s t i n g u i s h e d by i t s r e c o g n i t i o n of l o g i c a l d a t a
r e l a t i o n s h i p s beyond t h o s e of t h e simple d a t a item/record r e l a t i o n s h i p s o f t r a d i t i o n a l f i l e processing.
It does t h i s v i a an SD (schema d e f i n i t i o n )
i n t e r f a c e through which t h e u s e r s p e c i f i e s t h e r e l a t i o n s h i p s t h a t a r e t o b e m a i n t a i n e d i n t h e d a t a base.
The r e s u l t i n g l o g i c a l d e s c r i p t i o n (schema) i s
s t o r e d s e p a r a t e l y from t h e p h y s i c a l d a t a and c o n s u l t e d by t h e DBMS whenever storage o r r e t r i e v a l requests a r e carried-out.
A s i l l u s t r a t e d i n F i g u r e 2f it
i s l i k e l y t h a t f u t u r e DBMS's w i l l become p a r t i a l l y s e l f - c o n t a i n e d by p r o v i d i n g o t h e r non-procedural i n t e r f a c e s a s h a s been done by t h e s e l f - c o n t a i n e d FMS's. Although i n d i v i d u a l packages w i t h i n each c l a s s d i f f e r g r e a t l y i n t h e r a n g e o f f e a t u r e s o f f e r e d , Table 2 summarizes t h e c a p a b i l i t i e s of each c l a s s of system i n t e r m s of t h e non-procedural
i n t e r f a c e s t h a t a r e u s u a l l y provided.
In
t h e f o l l o w i n g s e c t i o n s we d e s c r i b e t h e main f e a t u r e s of each t y p e of system a s r e v e a l e d by t h e survey q u e s t i o n n a i r e d e s c r i b e d i n Appendix 110 4.2
F i l e Access Methods These a r e designed t o be a c c e s s e d v i a host-language
programs such a s
BASIC, and PL/I.
T h e i r purpose i s t o p r o v i d e f a s t randam and/or s e q u e n t i a l
access t o f i l e s .
Two of t h e surveyed systems f a l l i n t h i s category.
Both
a l l o w r e t r i e v a l from f i l e s based on m u l t i p l e key v a l u e s and a l l o w f o r more t h a n one f i l e t o be simultaneously open.
One of t h e systems (SUPERKRAM) u s e s a
VSAM-like f i l e s t r u c t u r e ; t h e o t h e r (MICRO-B+) a B-tree approach.
They a r e
d e s i g n e d f o r use by programmers r a t h e r t h a n end-users. 4.3
Self-Contained F i l e Management Systems These systems a t t e m p t t o p r o v i d e a s i n g l e i n t e r f a c e through which a l l f i l e
maintenance and r e t r i e v a l f u n c t i o n s can be perfonned.
A s i n d i c a t e d by T a b l e 1
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
Table 2 Non-procedural I n t e r f a c e s P r o v i d e d by V a r i o u s Systems
2.2
1.1 File Access Method
1.2.1 Totally Self-contained FMS
1.2.2 Partially Self-contained FMS
1.3 Application Development System
2.1 DBMS
F i l e D e s c r i p t i o n (FD) (itemlrecord d e f i n i t i o n s )
No
Yes
Yes
Yes
Yes
Yes
Schema D e s c r i p t i o n (SD) (Complex d a t a r e l a t i o n ships)
No
No
No
No
Yes
Yes
Loading Data (LD)
No
Yes
Yes
Yes
No
Yes
Single f i l e updates
Yes
Yes
Yes
No
No
Computed f i e l d s
Usually
Usually
Yes
No
Yes
Yes
Yes
No
Yes
No
Sometimes
Yes
No
Yes
I n f o r m a t i o n R e t r i g v a l (IR) S i n g l e f il.e/muLtipile k e y s Multiple files/multiple keys Report G e n e r a t i o n (RG) Columnar r e p o r t s Job Processing (JP) Master/transaction f i l e llpdat e
Sometimes
Sometimes
DBMS with Interfaces
Sometimes
Yes
Yes
Yes
No
Yes
No
No
Yes
No
No
t h i s c a t e g o r y r e p r e s e n t s t h e l a r g e s t number of a v a i l a b l e s o f t w a r e packages. They p r o v i d e f a c i l i t i e s f o r r e c o r d d e f i n i t i o n , d a t a e n t r y , update, r e t r i e v a l Most o f
and d e l e t i o n combined w i t h s o r t and r e p o r t g e n e r a t i o n c a p a b i l i t i e s .
t h e s e systems a r e designed t o a l l o w a c c e s s t o only one f i l e a t a time and l e a d t h e u s e r , v i a a s e r i e s o f f o r m a t t e d menu s c r e e n s , through t h e v a r i o u s functions.
They a r e geared f o r t h e naive u s e r and a r e f a i r l y s u c c e s s f u l i n
a l l o w i n g a businessman with a l i m i t e d knowledge of computers t o run t h e system unassisted. The systems f a l l i n g i n t h i s c a t e g o r y a r e : DBMASTER, INFO-MANAGER, SELECTOR 111.
MAXI-MICRO-MANAGER,
ANXYST, CCA, CROMEMCO DBMS,
0s-DMS,
O Z Z , PROFILE 11 and
The f o l l o w i n g i s an examination of t h e most common f e a t u r e s of
t h e s e packages. General C h a r a c t e r i s t i c s
- The
f i l e management systems surveyed a r e a l l
l e s s t h a n 2 y e a r s o l d with a l a r g e i n c r e a s e i n number t h i s y e a r . p r i c e d between $100 and $700.
They a r e
They have v a r y i n g numbers of u s e r s from a few
f o r t h e j u s t r e l e a s e d systems t o more t h a n 1000 f o r t h e more e s t a b l i s h e d systems.
They a r e designed f o r l i s t management,
and a c c o u n t i n g a p p l i c a t i o n s .
simple m a s t e r f i l e maintenance
The systems a r e evenly s p l i t between t h o s e
w r i t t e n i n a high l e v e l language ( u s u a l l y BASIC) and t h o s e w r i t t e n i n assembler o r machine code.
They a r e a l s o evenly s p l i t between t h o s e t h a t can run o n l y a s
a s e p a r a t e a p p l i c a t i o n and t h o s e t h a t a l s o a l l o w i n v o c a t i o n from user-provided a p p l i c a t i o n programs. System Requirements
- The
systems surveyed were of two t y p e s
-
those
designed t o run on one m a n u f a c t u r e r ' s hardware and o p e r a t i n g system and t h o s e designed t o run on a v a r i e t y of machines u s u a l l y w i t h t h e CP/M o p e r a t i n g system.
The s t o r a g e r e q u i r e d v a r i e s from 24 k t o 56 k w i t h most systems
r e q u i r i n g approximately 48K.
Most systems run on 1 o r 2 d i s k e t t e s and can
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
A language i n t e r f a c e t o BASIC i s r e q u i r e d i n about h a l f
accomodate h a r d d i s k s . o f t h e systems.
A l l r e q u i r e some d i s p l a y device.
Some a l s o r e q u i r e a d i r e c t
c u r s o r a d d r e s s CRT and a p r i n t e r . User I n t e r f a c e
- The
d a t a management system: u p d a t e and maintenance,
following a c t i v i t i e s involve user i n t e r a c t i o n with a (1)
F i l e d e f i n i t i o n , ( 2 ) Entry of new d a t a , ( 3 ) F i l e
( 4 ) Ad-hoc d a t a base i n q u i r y ,
( 5 ) G e n e r a t i o n of r e p o r t s
and s p e c i a l forms.
The i n t e r f a c e s provided by t h e surveyed systems f a l l i n t h e f o l l o w i n g categories:
( 1 ) System prompts,
Command language
( 2 ) Menu s e l e c t i o n , ( 3 ) Screen forms, ( 4 )
.
G e n e r a l l y t h e systems p r o v i d e a combination of methods and a uniform s t y l e o f i n t e r a c t i o n f o r each of t h e f i v e a c t i v i t i e s l i s t e d above. a r e i n v a r i a b l y used
-
System prompts
o f t e n i n combination w i t h ( a n d i n p a r t i c u l a r t o c o n t r o l
t h e u s e o f ) one o r more of t h e o t h e r t y p e s of i n t e r f a c e .
Only a few of t h e
systems p r o v i d e a "Help1' f e a t u r e t o g e n e r a t e a l i s t of a l l o w a b l e u s e r r e s p o n s e s t o each prompt.
S e l e c t i o n from a menu i s t h e most p o p u l a r i n t e r f a c e provided
t o guide t h e u s e r through t h e v a r i o u s program o p t i o n s .
File definition, data
;*try and f i l e maintenance a r e u s u a l l y handled by prompting f o r t h e r e q u i r e d i n f o r m a t i o n on an item-by-item
basis.
S e v e r a l systems employ s c r e e n forms and
cursor-addressing t o allow a " f i l l - i n - t h e
blanks" mode of d a t a e n t r y .
t h e s e systems a l l o w u s e r s t o d e f i n e t h e i r own forms.
Some of
A combined prompt and
command language approach i s used i n some of t h e systems t o a l l o w u s e r s t o compose r e t r i e v a l r e q u e s t s i n v o l v i n g s e v e r a l s e l e c t i o n c r i t e r i a . Data S t r u c t u r e s types*
- All
of t h e systems a l l o w c h a r a c t e r and i n t e g e r d a t a
Many systems have a d a t e d a t a t y p e and some i n c l u d e o t h e r s such a s
b i n a r y , l o g i c a l , and r e a l .
The,systems1 l i m i t s a s t o f i e l d s i z e , record s i z e ,
and f i e l d l a b e l s i z e v a r y widely.
A t t h e low end of t h e s c a l e maximum r e c o r d
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
s i z e i s l i m i t e d t o about 250 b y t e s f o r t h r e e of t h e systems which can b e restrictive.
For t h e most p a r t f i l e s i z e i s only l i m i t e d by d i s k c a p a c i t y .
Almost a l l o f t h e systems r e q u i r e t h e u s e of f i x e d l e n g t h r e c o r d s w i t h o u t r e p e a t i n g f i e l d s o r groups of f i e l d s .
(i.e.
Most packages s u p p o r t computed f i e l d s
f i e l d c o n t e n t computed by package u s i n g a p r e v i o u s l y d e f i n e d f o r m u l a ) .
Only one system a l l o w s m u l t i p l e r e c o r d t y p e s w i t h i n t h e same f i l e (e.g.
header
and t r a i l e r r e c o r d s ) . Most systems use m u l t i p l e a c c e s s t e c h n i q u e s w i t h r e l a t i v e r e c o r d number and primary key b e i n g t h e most f r e q u e n t l y encountered comSination. t h e systems s u p p o r t secondary key indexes.
Five of
G e n e r a l l y t h e i n d e x e s a r e only
v a l i d f o r a s t a t i c f i l e and have t o be r e b u i l t i n a s e p a r a t e s t e p a f t e r r e c o r d s have been added.
Only t h r e e of t h e systems a l l o w more t h a n one f i l e t o be open
a t a time. F i l e Definition
- All
aid i n f i l e definition.
of t h e packages p r o v i d e an o n l i n e s c r e e n e d i t o r t o
Users a r e f i r s t p r e s e n t e d with a menu of system func-
t i o n s among which i s f i l e d e f i n i t i o n .
They a r e t h e n l e d through a s e r i e s of
s t e p s t o d e f i n e f i l e names, r e c o r d l a y o u t s , and f i e l d names and c h a r a c t e r i s tics.
The r e s u l t i n g f i l e d e f i n i t i o n i s s t o r e d and used t o prompt t h e u s e r upon
data entry.
Only two of t h e systems a l l o w m o d i f i c a t i o n s t o be made t o t h i s
f i l e d e f i n i t i o n a f t e r i t s i n i t i a l c r e a t i o n without f i l e reconstruction. Data Entry and Update and update f a c i l i t i e s .
- All
of t h e packages p r o v i d e i n t e r a c t i v e d a t a e n t r y
Like f i l e d e f i n i t i o n , t h i s i s u s u a l l y done v i a a s e r i e s
of menu s c r e e n s and prompts.
Most o f t e n t h e system prompts t h e u s e r f i e l d - b y -
f i e l d which can be time consuming i f a l a r g e amount of d a t a i s t o be e n t e r e d a t one s e s s i o n e s p e c i a l l y a t o r i g i n a l f i l e l o a d i n g .
Some of t h e packages r e q u i r e
t h e f i l e t o be s o r t e d o r some u t i l i t y t o be run immediately a f t e r c r e a t i o n i n o r d e r t o c r e a t e t h e index o r p o i n t e r l i s t f o r keyed a c c e s s .
A few packages
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
check t h e i n p u t f o r v a l i d i t y (e.g.
no a l p h a s allowed i n numeric f i e l d s ) .
Record u p d a t e s f o r t h e most p a r t have t o be performed by manually a c c e s s i n g each r e c o r d u n l e s s t h e u s e r w r i t e s a s e p a r a t e b a t c h program.
The r e c o r d i s
a c c e s s e d by i t s r e l a t i v e r e c o r d number o r primary key, t h e new v a l u e p l a c e d i n t h e a p p r o p r i a t e f i e l d and t h e r e c o r d s t o r e d .
A few packages p r o v i d e t h e
f a c i l i t y t o update a l l r e c o r d s i n a c l a s s , o r which meet some c r i t e r i a . g r e a t l y enhances system performance f o r across-the-board u s u a l l y handled i n t h e same way a s updates.
changes.
This
Deletes a r e
The packages a r e about evenly
s p l i t a s t o whether t h e space occupied by a d e l e t e d r e c o r d i s immediately reusable.
A few systems allow f o r r e s t o r a t i o n of d e l e t e d r e c o r d s i f f i l e
compaction h a s n o t been performed. Information Retrieval
-
A l l of t h e packages provide some r e c o r d r e t r i e v a l
f a c i l i t y b u t v a r y widely a s t o t h e i r c a p a b i l i t i e s .
Most a l l o w r e t r i e v a l v i a
r e l a t i v e r e c o r d number, primtlry, and secondary keys. Boolean o p e r a t o r s and range v a l u e s f o r key r e t r i e v a l .
A number a l s o a l l o w A few p r o v i d e t h e
f a c i l i t y t o supply o n l y a p a r t i a l key, o r a key w i t h imbedded wild-card characters.
Two of t h e systems p r o v i d e " i n s t r i n g " s e a r c h c a p a b i l i t i e s t o
d i s p l a y r e c o r d s matching a p a r t i c u l a r s t r i n g i n any f i e l d .
Some systems
d i s p l a y t h e f i r s t r e c o r d s a t i s f y i n g t h e s u p p l i e d c r i t e r i a b u t most d i s p l a y a l l t h e r e c o r d s which meet t h e c r i t e r i a .
Some systems a l s o keep t r a c k of t h e
c u r r e n t p o s i t i o n i n t h e f i l e and a l l o w a c c e s s t o t h e n e x t o r p r e v i o u s r e c o r d . Report Generation
-
A l l of t h e systems p r o v i d e r e p o r t g e n e r a t i o n
f a c i l i t i e s i n t h e form of columnar r e p o r t s u s i n g f i e l d names a s headings.
Some
a l l o w t h e u s e r t o supply headings o t h e r t h a n f i e l d names, t o g e n e r a t e t o t a l s and s u b t o t a l s based on a change i n a f i e l d v a l u e ( l e v e l b r e a k s ) , and t o perform some s t a t i s t i c a l a n a l y s i s .
p one
of t h e systems p r o v i d e g r a p h i c d i s p l a y s b u t
most have m a i l i n g h b e l p r i n t c a p a b i l i t y .
Most s y s t e n s a l l o w r e p o r t f o r m a t s t o
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
be s t o r e d f o r r e p e a t e d use.
Most a l l o w t h e r e p o r t o u t p u t t o be d i r e c t e d t o t h e
terminal o r the printer a t the user's discretion. Special Features features.
- Many
of t h e systems surveyed had v a r i o u s s p e c i a l
A machine language s o r t seemed t o be t h e most common e x t r a .
Some of
t h e s o r t s were q u i t e s o p h i s t i c a t e d w i t h r e c o r d include/exclude and m u l t i - l e v e l sort criteria.
Some a l s o a l l o w Boolean o p e r a t o r s i n t h e s o r t c r i t e r i a .
a d d i t i o n t h e systems surveyed p r o v i d e d v a r i o u s l y : compaction r o u t i n e s , reporting.
In
date routines, data
f i l e r e o r g a n i z a t i o n u t i l i t i e s , and space a l l o c a t i o n
Only one of t h e systems surveyed provided any d a t a d i c t i o n a r y A few provide password p r o t e c t i o n .
support.
Performance
- Access t i m e s
t o i n d i v i d u a l r e c o r d s and throughput i n t e r m s
o f number of r e c o r l u p d a t e s p e r minute f o r batch p r o c e s s i n g a r e dependent, among o t h e r t h i n g s , on t h e t y p e of a u x i l l i a r y s t o r a g e d e v i c e used.
Depending
o n t h e a c c e s s method employed performance can degrade s e r i o u s l y w i t h l a r g e f i l e s i z e s and l o n g s e a r c h keys.
Access t i m e s i n t h e range from .5 t o 2.5
seconds
p e r r e c o r d were r e p o r t e d f o r f i l e s i z e s l e s s t h a n 1 0 0 0 r e c o r d s . Support
-
Generally t h e s e systems can be i n s t a l l e d i n l e s s t h a n a day a n d
used s u c c e s s f u l l y w i t h i n two.
A r e a l l y complete u n d e r s t a n d i n g of a l l t h e
f a c i l i t i e s would probably be a c h i e v e d w i t h a month's u s e of t h e package. o f t h e systems a r e s o l d w i t h some documentation. t h r o u g h t h e f u n c t i o n s i n a step-by-step
manner.
All
Most manuals l e a d t h e u s e r There a r e a number of u s e r
groups f o r each of t h e hardware m a n u f a c t u r e r s which w i l l p r o v i d e h e l p t o new users.
Usually t h e d i s t r i b u t o r o f a package w i l l p r o v i d e u s e r s w i t h some
i n i t i a l h e l p i n s e t t i n g up f i l e s b u t few p r o v i d e any o n - s i t e s u p p o r t .
Most
vendors p r o v i d e upgrade n o t i f i c a t i o n f o r t h e i r customers.
s-sry
- The
f i l e management systems c u r r e n t l y a v a i l a b l e p r o v i d e t h e
s m a l l businessman with l i t t l e knowledge of computing t e c h n i q u e s w i t h a f a s t
e a s y method t o s t o r e and r e t r i e v e d a t a .
They a r e aimed a t t h e u s e r who does
one r e c o r d lookup o r update a t a time with minimal amounts of c a l c u l a t i o n o r They provide such a u s e r with simple r e p o r t s w i t h a
s t a t i s t i c a l analysis. minimum amount: of work.
A s a b u s i n e s s grows i t s d a t a p r o c e s s i n g needs change.
New i n f o r m a t i o n
must be c a r r i e d i n f i l e s , t r a n s a c t i o n volumes i n c r e a s e , and more complex d a t a manipulation i s required.
The systems c u r r e n t l y a v a i l a b l e do n o t provide
a d e q u a t e l y f o r t h i s t y p e of growth.
Usually f i l e s can n o t be modified a f t e r
implementation and complex a p p l i c a t i o n s must be user-written.
4.4
w l i c a t i o n Development Systems These systems a r e designed t o h e l p u s e r s with a m a l l amount of computer
e x p e r i e n c e and i n t i m a t e knowledge of t h e i r p r o c e s s i n g requirements.
Users
d e f i n e t h e sequence of f i l e p r o c e s s i n g s t e p s necessary f o r t h e i r a p p l i c a t i o n by answering prompts o r u s i n g a s p e c i a l command language provided by t h e package. The r e s u l t i s a customized stand-alone system f o r performing t a s k s such a s i n v e n t o r y c o n t r o l , accounts payable o r r e c e i v a b l e , s a l e s a n a l y s i s o r g e n e r a l ledger. Four of t h e systems i n T a b l e 1 have been designated a s A p p l i c a t i o n Development Systems because t h e y p r o v i d e f a c i l i t i e s t o a s s i s t i n u p d a t i n g m a s t e r f i l e s from t r a n s a c t i o n f i l e s .
A l l f o u r of t h e systems p r o v i d e s p e c i a l
i n t e r f a c e s (prompts, menus o r s c r e e n f o r m a t s ) f o r f i l e d e f i n i t i o n , d a t a e n t r y , update, screen formatting, i n f o r m a t i o n r e t r i e v a l and r e p o r t g e n e r a t i o n .
Three
of t h e systems allow t h e m a s t e r f i l e update f u n c t i o n t o be performed u s i n g user-defined procedures. PRISM/ADS ( a n e x t e n s i o n 05 t h e PRISM/IMS f i l e management system) i s e s s e n t i a l l y a s i n g l e f i l e i n f o r m a t i o n r e t r i e v a l s f s t e m when used i n a stand-alone fashion.
When c a l l e d from a u s e r - w r i t t e n B A S I C h o s t Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
p r o p a m PRISM/ADS p r o v i d e s s c r e e n format, m a s t e r f i l e management and r e p o r t generation f a c i l i t i e s .
T r a n s a c t i o n f i l e s ( g e n e r a t e d e x t e r n a l t o PRISM) can be
p r o c e s s e d by t h e a p p l i c a t i o n program and matched with master f i l e r e c o r d s u s i n g PRISM.
FMS-80 and SELECTOR IV a l l o w m u l t i - f i l e r e t r i e v a l and p r o c e s s i n g .
Master f i l e u p d a t e s can be performed by u s e r - d e f i n e d p r o c e d u r e s u s i n g computat i o n a l and c o n d i t i o n a l s t a t e m e n t s i n languages p r o v i d e by t h e packages
.
The f o u r t h system, CBS, a l l o w s u s e r s t o d e f i n e t h e i r p r o c e s s i n g r e q u i r e ments non-procedurally by s p e c i f y i n g one o r more menus. s p e c i f y t h a t t h e s t e p s i n a n o t h e r menu be performed.
A menu i t e m may
Each job s t e p i n a m u l t i -
f i l e a p p l i c a t i o n may be d e f i n e d i n terms of t h e i n p u t and o u t p u t f i l e s used and t h e CBS sub-program t h a t i s t o be performed.
I n t h i s way i t i s e a s y t o d e f i n e
simple update o p e r a t i o n s i n v o l v i n g a d d i t i o n t o o r s u b t r a c t i o n from a m a s t e r f i l e d a t a i t e m v a l u e o r movement of d a t a t o o r from t h e t r a n s a c t i o n f i l e .
Up
t o e i g h t job s t e p s and twenty f i l e s may be i n v o l v e d i n a s i n g l e a p p l i c a t i o n . Systems l i k e t h e s e make it e a s i e r t o customize b u s i n e s s a p p l i c a t i o n s and may b e used i n c r e a s i n g l y i n t h e f u t u r e by b o t h s o f t w a r e d e v e l o p e r s and end users.
Unlike t h e DBMS systems t o be d e s c r i b e d i n t h e n e x t s e c t i o n t h e y
c o n c e n t r a t e on p r o c e s s i n g l o g i c r a t h e r t h a n on t h e l o g i c a l r e l a t i o n s h i p s among d a t a items.
C a r e f u l d e s i g n and management o f t h e t r a n s a c t i o n and m a s t e r f i l e s
i s n e c e s s a r y t o avoid p r o l i f e r a t i o n of redundant d a t a and d i f f i c u l t system maintenance problems.
4.5
DATA BASE MANAGEMENT SYSTEMS DBMS systems can be c l a s s i f i e d a c c o r d i n g t o t h e d a t a model ( l o g i c a l view
of d a t a ) on which t h e y a r e based.
There a r e t h r e e p r i n c i p l e models;
h i e r a r c h i c a l , network and relational.
Two of t h e systems surveyed (MDBS and
Microseed) a r e network d a t a b a s e systems g e n e r a l l y conforming t o t h e d e s i g n
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
p r i n c i p l e s d e s c r i b e d i n t h e CODASYL Data Base Task Group r e p o r t , S e r i e s 20/DBMS and CONDOR DBM-1 a r e based on a r e l a t i o n a l d e s i g n ,
[21.
CONDOR
[31.
MDBS
h a s a s i m p l e r v e r s i o n , HDBS, which implements an h i e r a r c h i c a l d a t a view. A d a t a b a s e management system p r o v i d e s a means f o r many d i f f e r e n t
a p p l i c a t i o n programs t o s h a r e t h e same d a t a f i l e s .
This g r e a t l y reduces
redundancy of d a t a s t o r a g e and t h e r e s u l t i n g update problems.
Multiple
a p p l i c a t i o n s can s h a r e common d a t a because t h e DBMS a l l o w s each program t o a c c e s s any d a t a it needs i n any r e q u i r e d o r d e r . By way of c o n t r a s t t r a d i t i o n a l d a t a p r o c e s s i n g w i t h o u t a DBMS w i l l r e l a t e a program t o i t s d a t a by m a i n t a i n i n g m u l t i p l e f i l e s and u s i n g s o r t and matchmerge o p e r a t i o n s .
Note t h a t t h i s can p r o v i d e a n e f f i c i e n t method o f ~ r o c e s s i n g
a p p l i c a t i o n s w i t h l a r g e volumes of t r a n s a c t i o n s .
However, a program must be
w r i t t e n and t h e r e q u i s i t e f i l e s c r e a t e d f o r each a p p l i c a t i o n *
This usually
means t h a t m u l t i p l e c o p i e s of t h e same d a t a item must be m a i n t a i n e d .
It a l s o
l e a d s t o i n f l e x i b l e systems s i n c e new programs and f i l e s need t o be s e t - u p e a c h t i m e a new i n f o r m a t i o n r e q u e s t h a s t o be s a t i s f i e d . Simple h i e r a r c h i c a l r e l a t i o n s h i p s (eg. one employee t o many d e p e n d e n t s ) can o f t e n be handled e f f i c i e n t l y i n t r a d i t i o n a l f i l e p r o c e s s i n g by s p e c i f y i n g r e c o r d s with a r o o t segment (eg. employee) and r e p e a t i n g groups ( e g o dependents).
H i e r a r c h i c a l r e t r i e v a l can a l s o be achieved by a user-maintained
coding scheme and t h e u s e o f p a r t i a l keys o r wild-card t h e f i l e management systems d i s c u s s e d e a r l i e r . d i f f i c u l t t o r e p r e s e n t e i t h e r ( 1 ) many-to-many
c h a r a c t e r s i n some o f
However, w i t h o u t a DBMS i t i s r e l a t i o n s h i p s (eg. s u p p l i e r s
supply many d i f f e r e n t p a r t s ; a g i v e n p a r t may be s u p p l i e d by many s u p p l i e r s ) o r ( 2 ) r e l a t i o n s h i p s where a given r e c o r d h a s more t h a n one owner (eg. a l i n e i t e m r e c o r d needs t o be r e l a t e d t o a ' purchase Order header r e c o r d , a s u p p l i e r r e c o r d and an i t e m r e c o r d ) .
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
The Two Network Systems B e f o r e a network DBMS can be used it i s n e c e s s a r y t o d e f i n e a d a t a base
' schema'
d e s c r i b i n g t h e d a t a items, r e c o r d t y p e s and i n t e r r e c o r d r e l a t i o n s h i p s
o r 'sets'
t h a t a r e to be maintained i n t h e d a t a b a s e .
MDBS u t i l i z e s a s p e c i a l
e d i t o r r o u t i n e v i a which t h e u s e r d e f i n e s t h e d a t a base i n a non-procedural ' d a t a d e f i n i t i o n language'
I n MICROSEED t h i s s t a t e m e n t i s w r i t t e n to a
(DDL).
f i l e u s i n g t h e normal system e d i t o r .
A g r a p h i c a l r e p r e s e n t a t i o n of t h e
i n f o r m a t i o n s t o r e d i n a t y p i c a l schema i s shown i n F i g u r e 4 below. MICROSEED f o l l o w s t h e CODASYL 'subschema'
concept and r e q u i r e s t h a t a
s e p a r a t e f i l e be generated f o r each a p p l i c a t i o n program d e s c r i b i n g t h e s u b s e t of t h e schema t h a t w i l l be u t i l i z e d . DDL a s t h e schema.
The subschemas a r e d e f i n e d u s i n g t h e same
Subschemas can be u s e f u l i n p r o v i d i n g d a t a independence and
p r o v i d e a form o f s e c u r i t y p r o t e c t i o n s i n c e a n a p p l i c a t i o n can o n l y a c c e s s t h o s e p a r t s of t h e schema t h a t have been d e c l a r e d i n i t s sub-schema. p a s s e s t h i s s t e p b u t i n c o r p o r a t e s a 'data-group' program i n t e r f a c e w i t h t h e DBMS.
MDBS by-
concept i n t o t h e h o s t language
T h i s a l l o w s t h e u s e r t o s p e c i f y a s u b s e t of
d a t a i t e m s which can be a c c e s s e d u s i n g a group name. Having d e f i n e d t h e s t r u c t u r e of t h e d a t a base i n t h i s manner t h e next s t e p
i s t o load t h e data i n t o t h e database. program i n a host-language
To do t h i s t h e u s e r must w r i t e a
such a s FORTRAN, BASIC o r COBOL.
The h o s t language
program r e a d s t h e u s e r ' s d a t a f i l e s and s t o r e s t h e d a t a i n t h e d a t a b a s e f i l e by issuing 'calls'
t o t h e DBMS.
Data Manipulation Language'
T h i s ' e x t e n s i o n to t h e h o s t language' i s c a l l e d a
.
(DML)
I n g e n e r a l a c e s s t o t h e d a t a f o r a p p l i c a t i o n s can be o b t a i n e d e i t h e r v i a a high-level
'query language' o r by w r i t i n g programs i n t h e h o s t language (which
a c c e s s e s t h e d a t a v i a DML c a l l s a s d e s c r i b e d a b o v e ) . d e s c r i b e d l a t e r have used t h e host-language
The a p p l i c a t i o n s t o be
approach.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
I n i t i a l e n t r y to t h e network of r e c o r d s i s o b t a i n e d v i a a s p e c i a l 'System" r e c o r d i n MDBS; t h e r e a f t e r p o i n t e r c h a i n s a r e followed t o move from one r e c o r d t y p e ( e g . O r g a n i z a t i o n ) t o a n o t h e r ( e g . Employee).
MICROSEED a l l o w s i n i t i a l
e n t r y t o an i n s t a n c e of a r e c o r d i n t h e network v i a a DBMS-supplied h a s h i n g f u n c t i o n , t h e r e a f t e r p o i n t e r c h a i n s a r e followed i n a record-by-record
fashion
a s above. Both MDBS and MICROSEED i n c o r p o r a t e s i g n i f i c a n t e x t e n s i o n s to t h e o r i g i n a l CODASYL s p e c i f i c a t i o n .
b a s i c package. ships.
MICROSEED i n c o r p o r a t e s a query language a s p a r t of t h e
MDBS a l l o w s a d i r e c t r e p r e s e n t a t i o n of many-to-many
relation-
T h i s can s i g n i f i c a n t l y d e c r e a s e b o t h t h e complexity of t h e d a t a b a s e
and subsequent p r o c e s s i n g . o v e r a s i n g l e record-type
MDBS a l s o a l l o w s set r e l a t i o n s h i p s t o be d e f i n e d
t h i s a l l o w s d i r e c t r e p r e s e n t a t i o n of b i l l - o f i n s t a n c e s of ' p a r t s '
records.
s e p a r a t e add-on f e a t u r e .
For example,
( r a t h e r t h a n between two r e c o r d - t y p e s ) .
m a t e r i a l s r e l a t i o n s h i p s between
MDBS s u p p l i e s an i n t e r a c t i v e query language a s a
I n a d d i t i o n MDBS a l s o s u p p l i e s a s e p a r a t e ' d a t a
r e s t r u c t u r i n g ' package which a l l o w s item, r e c o r d and s e t r e l a t i o n s h i p s a s d e f i n e d i n an e x i s t i n g schema t o be changed under program c o n t r o l .
This
f e a t u r e can be very s i g n i f i c a n t i n a l l o w i n g u s e r s t o a d a p t t h e i r systems t o changing requirements. The R e l a t i o n a l S y s t z The two Condor systems a r e based on a r e l a t i o n a l view of d a t a . view a l l d a t a i t e m s a r e s t o r e d i n ' f l a t '
In t h i s
f i l e s o r 'relations' i e . there a r e no
r e p e a t i n g groups o r o t h e r h i e r a r c h i c a l r e l a t i o n s h i p s involved.
To g i v e maximum
f l e x i b i l i t y and s i m p l i c i t y t o t h e u s e r view, l o g i c a l d a t a base r e l a t i o n s h i p s between r e c o r d s a r e n o t e x p l i c i t y d e f i n e d by p o i n t e r s o r l i n k s a s i n t h e h i e r a r c h i c a l o r network models..
Instea6 relationships inherent i n the data a r e
r e a l i z e d by r e f e r e n c i n g keys t h a t a r e common t o more t h a n one r e l a t i o n .
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
The d a t a d e f i n i t i o n i n t e r f a c e s t o DBM-1and S e r i e s 20 u t i l i z e s c r e e n formats and a r e s i m i l a r t o t h o s e f o r many o t h e r systems i n t h i s study. M u l t i p l e 'views'
of each r e l a t i o n a r e p o s s i b l e ; each view may c o n t a i n a
d i f f e r e n t d e s c r i p t i o n of t h e d a t a items. U s e r s can a c c e s s t h e d a t a base u s i n g a high l e v e l language based on an
a l g e b r a i c approach.
This language p e r m i t s u s e r s t o form new r e l a t i o n s f o r
subsequent temporary o r permanent s t o r a g e o r f o r use i n r e p o r t s o r i n answer t o queries.
The new r e l a t i o n s a r e s u b s e t s of e x i s t i n g r e l a t i o n s o r a r e o b t a i n e d
e i t h e r by appending one r e l a t i o n t o a n o t h e r o r by merging two r e l a t i o n s on a common key f i e l d . DBM-1 and S e r i e s 20 provide password p r o t e c t i o n and have r e p o r t generators.
They can be used i n e i t h e r i n t e r a c t i v e o r batch mode and can a l s o be
c a l l e d from host-language programs.
I n common with t h e ADS systems d e s c r i b e d
e a r l i e r it i s p o s s i b l e t o d e f i n e job streams t o perform t r a d i t i o n a l t r a n s a c t i o n processing.
5.
SURVEY O F DATA BASE MANAGEMENT SYSTEM USERS
We now d i s c u s s t h e r e s u l t s o b t a i n e d from a survey of u s e r s of one of t h e two network DBMS systems (MDBS) and t h e r e l a t i o n a l systems (Condor DBM-1 and Series 20).
Although t h e sample s i z e i s s m a l l w e f e e l t h a t t h e r e s u l t s a r e
i n t e r e s t i n g and i n d i c a t e t h e p o t e n t i a l f o r t h i s new a r e a of micro computer software. Table 3 summarizes some c h a r a c t e r i s t i c s of t h e u s e r sample. u s e r s were computer p r o f e s s i o n a l s .
Most of t h e
However, one non-professional u s e r with
o n l y one y e a r ' s programming e x p e r i e n c e was s u c c e s s f u l l y u s i n g t h e system.
All
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
o f t h e u s e r s i n t h e sample had r e c e i v e d a s s i s t a n c e from t h e vendor e i t h e r i n i n s t a l l i n g t h e system o r i n developing a p p l i c a t i o n s .
Sample S i z e = 10
.
Industry:
Government ( 3 1, p r o f e s s i o n a l ( 2 ) , Software i n d u s t r y ( 4 1, Microcomputer manufacturer ( 1 )
Average Data P r o c e s s i n g e x p e r i e n c e of p e r s o n s u s i n g DBMS = 4 y e a r s Hardware :
CPU c a p a c i t y : 64K(9 1 ; 5 6 ~1( Floppy d i s k ( 6 ) ; hard d i s k ( 4 )
A s s i s t a n c e from Vendor: A l l 10 u s e r s had r e c e i v e d a s s i s t a n c e from t h e vendor e i t h e r d u r i n g o r subsequent t o i n s t a l l a t i o n . Applications: The 10 u s e r s c i t e d 28 e x i s t i n g a p p l i c a t i o n s . new a p p l i c a t i o n s . User S a t i s f a c t i o n :
A l l were p l a n n i n g
A l l systems were r a t e d a s " v e r y s a t i s f a c t o r y " by a l l u s e r s .
TABLE 3 P r o f i l e o f DBMS Users
Table 4 c o n t a i n s some s t a t i s t i c s d e s c r i b i n g t h e DBMS a p p l i c a t i o n programs and d a t a bases.
Since t h e DBMS o c c u p i e s approximately 19k of memory ( i n c l u d i n g
page b u f f e r s ) and space must be allowed f o r a p p l i c a t i o n program b u f f e r s and t h e o p e r a t i n g system, t h e a p p l i c a t i o n programs must n e c e s s a r i l y b e r a t h e r m a l l . However t h e f u n c t i o n s performed by t h e DBMS i t s e l f g r e a t l y r e d u c e t h e n e c e s s a r y l e n g t h of programs when compared w i t h a non-data base environment.
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Host Language - A p p l i c a t i o n Programs No, o f L i n e s o f Code Max h u m Minimum 500 250
No. - o f - U s e r s
Language BASIC COBOL
Data Base S i z e s : Minimum
Maximum
,
3 M b y t e s , 10,000 r e c o r d s
50K b y t e s , 400 r e c o r d s
Complexity o f Data Base Minimum 2 5 2
Number of r e c o r d t y p e s T o t a l number of f i e l d s Number o f 1: n s e t s Number of m: n sets
Max im um 13 150 17
TABLE 4 C h a r a c t e r i s t i c s of E x i s t i n g DBMS ~ p p l i c a t i o n s(MDBS)
The lower p a r t o f Table 4 g i v e s a n i d e a of t h e l o g i c a l complexity of t h e d a t a b a s e s i n terms of t h e i n t r a - r e c o r d maintained.
and i n t e r - r e c o r d r e l a t i o n s h i p s
Figure 3 g i v e s a g r a p h i c a l r e p r e s e n t a t i o n of t h e schema f o r one o f
t h e user applications. r e c t a n g l e s R1, R2,...
I n t h e f i g u r e r e c o r d t y p e s a r e denoted by t h e and s e t - t y p e s by t h e d i r e c t e d a r c s .
For example, t h e
arrow from R9 t o R10 r e p r e s e n t s a 1:
many r e l a t i o n s h i p between R9 and R10 ( a n
i n s t a n c e of r e c o r d t y p e R9 may own
zero, one o r more i n s t a n c e s of r e c o r d
t y p e R10). many-to-many
The double-headed
arrow between R7 and R10 r e p r e s e n t s a
r e l a t i o n s h i p between t h e s e two r e c o r d t y p e s .
The range of d a t a base s i z k s f o r t h e r e l a t i o n a l systems was s i m i l a r t o t h a t f o r MDBS.
The number of r e l a t i o n s i n a d a t a base v a r i e d from a minimum o f
2 t o a maximum of 20 w h i l e t h e number of a t t r i b u t e s per r e l a t i o n v a r i e d from a
minimum o f 5 t o a maximum of 77.
R8
R1 b
-
A
t
>
SYSTEM.
*
>
R6
R4
R9
R5
I
DATABASE SIZE
3
R7
200,000 b y t e s
Number Of R e c o r d T y p e s T o t a l Number O f Fields Number o f S e t s :
1:n m:n
FIGURE 3 SCHEMA FOR ONE OF THE USER APPLICATIONS
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
From Table 4 and F i g u r e 3 it can be s e e n t h a t t h e u s e r s were t a k i n g advantage of t h e a b i l i t y of t h e DBMS t o m a i n t a i n q u i t e complex d a t a r e l a t i o n ships.
I n f a c t a number of t h e u s e r s i n d i c a t e d t h a t t h e y could n o t a t t e m p t
such a p p l i c a t i o n s without a DBMS.
The survey a l s o i n d i c a t e d t h a t some of t h e
u s e r s w e r e a t t e m p t i n g t o develop much more complex a p p l i c a t i o n s .
One M I I S u s e r
Another was d e v e l o p i n g
planned a d a t a base w i t h 60 r e c o r d t y p e s and 70 s e t s .
an i n t e g r a t e d d a t a base a p p l i c a t i o n w i t h 48 sub-programs each r e q u i r i n g more t h a n 40 K b y t e s of memory. 6.
CONCLUSION The d a t a management systems surveyed c o v e r a broad spectrum from s e l f -
c o n t a i n e d FMS's t o g e n e r a l purpose DBMS's.
Some of t h e FMS'S a r e p a r t i c u l a r l y
e a s y t o u s e ; however they have l i m i t e d c a p a b i l i t i e s .
A t t h e o t h e r extreme t h e
network DBMS's r e q u i r e programming s k i l l s b u t p r o v i d e g r e a t g e n e r a l i t y o f function.
These r e l a t i o n s h i p s a r e p l o t t e d i n F i g u r e 4.
A t r e n d a l r e a d y a p p a r e n t i n t h e i n d u s t r y i s a n a t t e m p t t o move t o w a r d s t h e
i d e a l system shown i n t h e upper r i g h t - h a n d c o r n e r of t h e f i q u r e . c o n s t r a i n e d by t h e c a p a b i l i t i e s of p r e s e n t micro-computer
This is
hardware, by o u r
l i m i t e d knowledge of what t h e end u s e r r e a l l y r e q u i r e s , and by o u r a b i l i t y t o produce r e l i a b l e ,
e f f i c i e n t software.
T h i s movement i s o c c u r i n g i n c r e m e n t a l l y from b o t h ends of t h e spectrum. F i l e management systems a r e a t t a i n i n g a c a p a b i l i t y t o p r o c e s s m u l t i p l e f i l e s and t o a s s i s t t h e u s e r i n developing a p p l i c a t i o n s .
Data base management
systems a r e b e i n g augmented by r o u t i n e s t o h e l p t h e u s e r l o a d d a t a i n t o t h e d a t a b a s e , by query languages and by r e p o r t g e n e r a t o r s . Competition i s f o r c i n g improvement i n t h e q u a l i t y of micro-computer management software.
However t h e r u l e of c a v e a t emptor s t i l l a p p l i e s .
data Some
systems w i l l c o n t i n u e t o have programming e r r o r s ; documentation i s n o t
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
A
EASE OF USE
IDEAL SYSTEM
GENERALITY OF FUNCTION
FIGURE 4 TRADE-OFF BETWEEN EASE OF USE AND GENERALITY OF FUNCTION
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
uniformly good; vendor $ay?port i s n e c e s s a r i l y l e s s t h a n t h a t provided i n t h e m i n i and maxi-computer markets; a d v e r t i s i n g claims and brochures sometimes u s e c o n f u s i n g terms.
Usually t h e software w i l l perform t h e i n t e n d e d b u s i n e s s
f u n c t i o n i f used properly.
However s u p p o r t i n g f u n c t i o n s such a s e r r o r r e p o r t s ,
f i l e maintenance and a u d i t t r a i l s a r e o f t e n l a c k i n g .
This forces u s e r s t o
l e a r n d e t a i l s of t h e o p e r a t i n g system and t o employ d a t a p r o c e s s i n g d i s c i p l i n e s and c o n t r o l s f o r which t h e y a r e unprepared.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
References
1.
ACM, Vol.
2.
CODASYL Data Base Task Group.
3.
Special Issue: Data-Base Management Systems, Computing S u r v e y s , 8 , No. 1, March 1976. A p r i l 1971 Report.
ACM, New York.
Codd, E.F., " A R e l a t i o n a l Model o f Data f o r L a r g e S h a r e d Data ~ a n k s " , Comm. 6 June 1970, p p 337-387.
ACM 1 3 , -
"The MARK IV System", Datamation, J a n u a r y 1968, pp 28-30.
4.
Postley, J.A.,
5.
S l o n i n , J a c o b , Michael W. F a r r e l l and P a u l S. F i s h e r , " A Survey o f MiniData Base Management Systems i n 1977", P r o c e e d i n g s F i r s t SIGMINI Symposium o n Small Systems, N e w York, 1978, pp 26-34.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
APPENDIX I LIST OF SURVEYED SYSTEMS AND VENDORS MDBS
ANALYST S t r u c t u r e d Systems Group, I n c . 5 208 Claremont Ave. Oakland, CA 94618
Micro Data Base Systems I n c . Box 248 Lafayette, I N 47902
CBS Dynamic M i c r o p r o c e s s o r Associates 545 F i f t h Avenue 10017 New York, NY
MICRO B+ F a i r Corn 2606 Johnson D r i v e 65201 Columbia, MO
CCA DATA MANAGER Personal Software Inc. 592 Weddell D r i v e Sunnyvale, CA 94086
MICRO-SEED I n t e r n a t i o n a l Data Base Systems I n c . 2300 Walnut S t r e e t 191 03 P h i l a d e l p h i a , PA
CONDOR SERIES 20/DBMS and CONDOR DBM-I Condor Computer Corp. 3989 R e s e a r c h P a r k D r . Ann Arbor, M I 48104
Ohio S c i e n t i f i c I n c . 1333 S. c h i l l i c o t h e Rd. 44202 Aurora, OH
CROMEMCO DBMS Cromemco I n c . 280 B e r n a r d o Ave. Mountain View, CA
02 z Commodore B u s i n e s s System I n c . 950 R i t t e n h o u s e Road 19406 N o r r i s t o w n , PA
0s-DNSNUCLEUS~'
94043
DBMASTER Stoneware Microcomputer Products 1930 4 t h S t r e e t San R a f a e l , CA 94901
PROFILE I1 Tandy C o r p o r a t i o n F o r t Worth, TX 76102
FMS-80 systems P l u s 1921 Rock S t r e e t Mountain View, CA
PRISM Micro A p p l i c a t i o n s Group 7300 C a l d u s Avenue V a n N u y s , CA 91406
94043
INFO MANAGER N o r t h S t a r Computers, 1440 4 t h S t r e e t 94710 B e r k e l e y , CA
Inc.
MAXI MICRO MANAGER Adventure I n t e r n a t i o n a l Box 3435 Longwood, FL 32750
SELECTOR I11 and SELECTOR IV Micro-Ap I n c . 9807 Danovan D r i v e 94583 San Ramon, CA SUPE RKRAM U n i t e d S o f t w a r e of America 750 T h i r d Avenue 10017 New York, NY
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APPENDIX I1 Survey Design A s mentioned p r e v i o u s l y an a t t e m p t was made t o examine both ( 1 ) t h e
a v a i l a b l e s o f t w a r e and ( 2 ) t h e u s e r s and t h e n a t u r e of t h e i r a p p l i c a t i o n s .
The
c o n t e n t s of t h e survey q u e s t i o n n a i r e s f o r t h e s e two groups a r e now b r i e f l y summarized.
-
Vendor Q u e s t i o n n a i r e
The q u e s t i o n n a i r e addressed t o t h e vendors was t e c h n i c a l i n n a t u r e . However it s t r e s s e d t h e f e a t u r e s provided from t h e u s e r ' s point-of-view t h a n from t h e view p o i n t of t h e s o f t w a r e system s p e c i a l i s t .
rather
It c o n t a i n e d
q u e s t i o n s s u i t a b l e f o r b o t h FMS and DBMS systems under t h e f o l l o w i n g g e n e r a l headings :
1.
General Information Vendor; p r i c e ; t y p e of system; d a t e of r e l e a s e ; number of u s e r s .
2.
System Requirements Micro p r o c e s s o r t y p e ; CPU r e q u i r e m e n t s and c a p a c i t y ; o p e r a t i n g systems; language i n t e r f a c e s .
3.
P h y s i c a l Data S t r u c t u r e s Data t y p e s supported; system l i m i t s on s i z e of f i e l d s , number of r e c o r d s , etc.;
4.
a c c e s s methods.
L o q i c a l Data S t r u c t u r e s Record s t r u c t u r e ; i n t e r r e c o r d r e l a t i o n s h i p s .
5.
Degree of Program and Data Independence S e p a r a t i o n of l o g i c a l and p h y s i c a l f i l e d e s c r i p t i o n s .
6.
User D e f i n i t i o n o f Records, F i e l d Names and Formats E d i t o r , prompting,
s c r e e n format f a c i l i t i e s .
Center for Digital Economy Research Stem School of Business IVorking Paper IS-81-69
7.
Data E n t r y and Update S p e c i a l d a t a e n t r y program; s c r e e n formats; s i n g l e o r group u p d a t e s and d e l e t e s ; s p a c e recovery.
8.
Information Retrieval F a c i l i t i e s Query language; prompts; s c r e e n formats; s e l e c t i o n c r i t e r i a p o s s i b l e .
9.
Report Generation F a c i l i t i e s Screen format g e n e r a t o r ; columnar r e p o r t s ; graphs; m a i l i n g l a b e l s ;
special
forms.
10.
U t i l i t y Routines Provided S o r t r o u t i n e s , m a s t e r f i l e / t r a n s a c t i o n f i l e update; d a t a base usage s t a t i s t i c s ; c a l e n d a r and d a t e r o u t i n e s ; d a t a compaction; a v a i l a b l e s p a c e reports.
11.
S e c u r i t y and I n t e g r i t y o f Data Base Pass-word p r o t e c t i o n ; update v a l i d a t i o n ;
12.
r e c o v e r y and back-u?
features.
Ease o f Use and Vendor Support Required s o p h i s t i c a t i o n of u s e r ; documentation; c o n s u l a t i o n , t r a i n i n g .
13.
Performance S t a t i s t i c s Time p e r r e t r i e v a l / u p d a t e ;
tuning.
I n a d d i t i o n t o o b t a i n i n g r e s u l t s from t h e vendor surveys we a l s o a r r a n g e d l i v e d e m o n s t r a t i o n s of most of t h e packages shown i n Table 1. User Q u e s t i o n n a i r e The o b j e c t i v e s of t h i s p a r t of t h e s t u d y were t o o b t a i n i n f o r m a t i o n about t h e u s e r s , t h e i r r e a c t i o n s t o t h e p a c k a g e s , t h e f e a t u r e s t h e y found most h e l p f u l and would most l i k e t o have, and i n f o r m a t i o n about t h e a p p l i c a t i o n s t o which t h e packages were devoted.
S l i g h t l y d i f f e r e n t q u e s t i o n n a i r e s were s e n t
t o t h e u s e r s of d a t a base management systems.
An a d d i t i o n a l o b j e c t i v e h e r e was
t o a s c e r t a i n t h e ccmplexity of t h e d a t a b a s e s t r u c t u r e s used.
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1.
User P r o f i l e I n d u s t r y ; s i z e of firm; d a t a p r o c e s s i n g environment; p e r s o n n e l ;
intensity
o f u s e of package.
2.
Hardware C o n f i g u r a t i o n CPU; o p e r a t i n g system; a u x i l l i a r y s t o r a g e ; hours of use of micro-computer.
3,
F i l e Management o r Data Base Management Package Name; vendor; v e r s i o n ; h o u r s of use of package; number of a p p l i c a t i o n s .
4.
User R a t i n g o f Packaqe S a t i s f a c t i o n w i t h package; documentation; problems i n i n s t a l l a t i o n ; q u a l i t y of a s s i s t a n c e provide.
5.
General Comments Major problems; b e s t f e a t u r e s ; new f e a t u r e s d e s i r e d .
6.
s p l i c a t i o n s f o r which Package Is Used S h o r t d e s c r i p t i o n s of p r e s e n t and f u t u r e a p p l i c a t i o n s .
7.
D e t a i l s of I n d i v i d u a l A p p l i c a t i o n s R e t r i e v a l only; update m a s t e r f i l e ; computations; g r a p h i c s ; number of f i l e s u s e d ; s i z e of f i l e s ; i n t e n s i t y of u s e of a p p l i c a t i o n .
8.
Complexity of Data Base Number of r e c o r d t y p e s and r e l a t i o n s h i p s
9.
A p p l i c a t i o n Programs Using Data Management Systems Source language; s i z e . Because of space l i m i t a t i o n s we can o n l y g i v e a n overview of t h e r e s u l t s of
t h e s e two surveys.
I n f a c t , t h e r e s u l t s of t h e u s e r survey a r e f u r t h e r
r e s t r i c t e d t o a m a l l s u b s e t of DBMS u s e r s .
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