COMPARISON
A N D M A P P I N G OF THE R E L A T I O N A L AND C O D A S Y L
-- AN A N N O T A T E D B I B L I O G R A P H Y
DATA MODELS
G a r y H. Sockut
Institute
for C o m p u t e r S c i e n c e s and T e c h n o l o g y
National B u r e a u of S t a n d a r d s
W a s h i n g t o n , DC 20234
Two of the b e s t - k n o w n data m o d e l s are
the
relational
model
and
the
C O D A S Y L model
(sometimes called the
DBTQ,
network,
or
data
structure
set
mode]~ .
There have
been m a n y e f f o r t s
at
comparing
the
two
mode3s
and
at
defining mappings between
them.
The
publications
3isted
in
this
bibliography
describe
some
o~
these
e f f o r t s and some related topics.
I invite
readers'
suggestions
for
additional
e n t r i e s for p o s s i b l e i n c l u s i o n in a future
bibliography.
% omit p u b l i c a t i o n s on the
more
general
topic
of
data
base
conversion.
C o m p u t i n g Surveys, ACM, vol.
], Mar. 1976, pp. 43-66.
For b a c k g r o u n d on the C O D A S Y L
sources such as:
model,
see
CODASYL
Data
Description
Language
Committee,
"Journal of D e v e l o p m e n t " ,
Materiel
Data
Management
Branch,
Dept.
of
Supply
and
Services,
C a n a d i a n Govt., Hull,
Que.,
Canada,
Jan. 1978.
C0DASYL
Programming
Committee,
"Data
Base
Report", ACM, Apr. 1971.
Language
Task
Group
R.
w.
Taylor
and
R.
L.
Frank,
"CODASYL
Data-Base
Management
Systems",
Computing
Surveys,
ACM,
vo]. 8, no. I, Mar. 197~, pp. 67-103.
I do not e v a l u a t e the p u b l i c a t i o n s , nor do
I g u a r a n t e e the truth of their s t a t e m e n t s .
Each p u b l i c a t i o n m a y r e f l e c t its
author's
opinions.
Also,
because
specifications
have evolved over the last ten years, some
statements
may
be
out
of
date.
The
b i b l i o g r a p h y r e v e a l s that the a u t h o r s have
not
reached
consensus
on e q u i v a l e n c e of
the models, nor on
the
models'
relative
merits,
nor
on
the
spelling
of
"data
base".
For b a c k g r o u n d
such as:
on both m o d e l s ,
see
sources
C.
J.
Date,
An
Introduction
to
Database
Sys'-~ems,
2nd
ed~,
Addison-Wesley, R~ing,
MA, 1977.
J.
Martin,
Computer
Data-Base
O r g a n i z a t i o n , 2n~--e~., P r e n t ~ ' ~ 6 ~ H a ~ [
E n g ] e w o o d Cliffs, NJ, 1977.
The m e n t i o n or lack o~ m e n t i o n of s p e c i f i c
commercial
products
does
not
imply
e n d o r s e m e n t or d i s a p p r o v a l by the National
B u r e a u of S t a n d a r d s .
I thank
John
Berg,
Joe
Collica,
Don
Deutsch,
Dennis
Fife,
Liz
Fong,
Len
G a l l a g h e r , Alan G o l d f i n e , T e r r y H a r d g r a v e ,
Be1
Leong-Hong,
Chuck
Sheppard, and Ben
Shneiderman,
whose
libraries
I
raided
innumerable
times
while
amassing
this
bibliography.
Terry
Hardgrave
and
Matt
Koll
reviewed
a draft
of
this
paper.
Several
authors
helped
me
obtain
publications.
The reader should
have
some
Familiarity
with data base m a n a g e m e n t and with the two
models.
For b a c k g r o u n d on the
relational
model, see sources such as:
Chamberlin,
Management
no.
E. F. Codd, "A
Relational
Model
of
Data
For
Large
Shared Data Banks",
Commun. ACM, vol.
13,
no.
6,
June
i~,
pp. ~77-387.
F o l l o w i n g each r e f e r e n c e , I d e s c r i b e
the
publication
briefly,
usually
by q u o t i n g
p a r t s of the a u t h o r ' s a b s t r a c t and/or main
text.
Often
I s u p p l e m e n t or replace the
a u t h o r ' s text with m y own words,
enclosed
in b r a c k e t s ([]).
I do not g u a r a n t e e that
an a u t h o r ' s a b s t r a c t
accurately
reflects
the c o n t e n t of the p u b l i c a t i o n .
D.
D.
Data-Base
8,
"Relational
Systems",
C O N T R I B U T I O N OF THE N A T I O N A L B U R E A U OF
Sm~NDARDS.
NOT S U B J E C T TO C O P Y R I G H T .
The a n n o t a t e d
55 -
bibliography
follows:
system
which
provides
a high
level
relational
data
interface".
[One
section
of the paper e x p l a i n s that the
interface] "is d e s i g n e d in such
a way
that
p r o g r a m s can be w r i t t e n on top of
it to
simulate
'navigation
oriented'
database
interfaces".
"In general our
strategy
will
be
to
represent
each
record
type
as
a
relation
and
to
represent
information
about
ordering
and
c o n n e c t i o n s b e t w e e n records in the
form
of
explicit
fields
in
the
corresponding
relations".
[Another
section
states
that
an]
"important
access path is a b i n a r y link".
"Binary
links are similar to the notion
of
an
owner
coupled
set
with
manual
membership
found
in
the
DBTG
specifications".
"The
main
use
of
b i n a r y links in System R is to
connect
child tuples to a parent based on value
m a t c h e s in one or more
fields".
[See
also (Lorie and Ni]sson, 1979)].
M. Adiba and C. De]obel, "The
Problem
of
the
Cooperation
Between
Different
D.B.M.S.",
G.
M.
Nijssen
(Ed.~ ,
Architecture
and
Models
in D a t a
Base
M a n a g e m e n t - Systems
(Proc.
IFIP
TC-2
Wor~~---Con~
on
Modelling in D a t a Base
Management
Syst.,
Jan.
1977),
N o r t h - H o l l a n d , Amsterdam, Neth., 1977 , pp.
1£5-1~6.
"We are investigating here the
problem
the
cooperation
between
several
DBM~.
This c o o p e r a t i o n can take place,
for
example,
via
a computer network.
we address o u r s e l v e s e s p e c i a l l y to
the
d e s c r i p t i o n of a globa] v i e w of several
d a t a bases".
"We
have
proposed
some
mechanisms
to
transform
any
program
w r i t t e n in terms of the global v i e w
in
programs
which
can be executed at the
local
data
base
level".
[See
also
(Adiba, De]obeY, and L6onard, 1976) and
(Aaiba and Portal, Igv~)J.
of
A u e r b a c h I n f o r m a t i o n M a n a g e m e n t Series
on
Data
Base M a n a g e m e n t , "A T a x o n o m y of Data
Structure
Models",
written
by
G.
C.
Everest,
Portfolio
21-03-~I,
Auerbach
Publishers, Pennsauken, NJ, 1979.
M. Adiba, C. De]obe], and M.
L6onard,
"A
Unified
Approach
for
Modelling
Data in
Logical Data Base Design", G.
M.
Nijssen
(Ed.) , M o d e l l i n g
in Data Base M a n a g e m e n t
S y s t e m s (Proc. TFIP TC-2 W o r ~ g
Conf.
on
Modelling
in
D a t a Base M a n a g e m e n t Syst.,
]an.
]97~) ,
North-Holland,
Amsterdam,
Neth., Iq7~, pp. 311-~38.
"This
Portfolio
presents
a
more
comprehensive
taxonomy
of
data
structures;
it d e s c r i b e s
the
basic
types of structures, h i g h l i g h t i n g their
major c h a r a c t e r i s t i c s
and
contrasting
them
through
the
use
of
a common
example".
[See also (Everest, 1976)].
"Here we examine h o w ... c o n v e r s i o n can
be
m a d e (in both ways) b e t w e e n network
and
relational
concepts,
using
the
DBTG-CODASML
and
SOCRATE
systems
as
examples".
[See
also
(Adiba
and
Delobel,
1977~
and (Adiba and Portal,
Igv~)].
C. W.
"We
propose
here
a
functional
architecture
of
a c o o p e r a t i o n system
For h e t e r o g e n e o u s
DBMS
in
a
network
environment"
[The paper assumes] "the
e x i s t e n c e of d i f f e r e n t local d a t a bases
already
in
use
under DBMSs like IMS,
Codasyl-]ike
systems,
SOCRATE,
re]ationa]
systems,
etc.".
"The
c o o p e r a t i o n system should be
able
...
to
provide facilities for creating and
m o d i f y i n g a global v i e w of these
local
data
bases".
[See
also
(Adiba
and
Delobel, ]977) and (Adiba, Delobe], and
L~onard, 19v6)].
C.
W.
Bachman,
"The
Role
Data
Approach
to Data S t r u c t u r e s " , Proc.
Conf. on D a t a Bases, Heyden,
Lon~,
J~y
198~, pp. 1-18.
is
a
database
Set
Model
Intl.
UK,
"This
paper
examines
the
Role
data
model
as
an e v o l u t i o n a r y step forward
in the s e q u e n c e of
data
models"
[and
c o m p a r e s it with other data models].
M.
M.
Astrahan
et
a].,
"System
R:
Relationa]
Approach
to
Database
M a n a g e m e n t " , ACM Trans. on D a t a b a s e Syst.,
vo]. 1, no. ~, June ~h"~6, pp. 9~-137.
R
in
"The relational debate, as I see it, is
over
style in retrieval languages, and
style, really, is o n l y one aspect of
a
data
base
system".
"I
accept
the
relational
view
and
the
data-structure-set
view
as
being
fundamentally compatible
as
they
are
applied
in
practice,
and I'd like to
d e m o n s t r a t e the e q u i v a l e n c e b e t w e e n the
two views".
M. Adiba and
D.
Portal,
"A
Cooperation
System
For
Heterogeneous
Data
Base
Management
Systems",
Information
Syst.,
P e r g a m o n Press, Oxford, UK, vol. 3, no. 3,
1978, Pp. ~ 9 - 2 1 5 .
"System
"The
Data
Structure
(Rustin, 1974), pp. 1-10.
Bachman,
Model",
W.
Bachman,
"Trends
in
Database
Management
-- 1975", Proc. Natl. C o m p u t e r
Conf.,
AFIPS,
vol.
44,
May
1975,
pp.
~-576.
C.
management
-
56
-
data
transfer,
and
a g l o b a l v i e w of
d i f f e r e n t data b a s e s in
a distributed
system.
The
author
states that with
some r e s t r i c t i o n s upon
the
relational
and
CODASYL
m o d e l s ] , "the ' e x p r e s s i v e
powers' of the m o d e l s are
equivalent".
[See also (Borkin, 1978)].
[One
section
says]
"I
consider
the
relational
model
and
the
data-structure-set
model
essentially
compatible
ann
subiect
to
t r a n s f o r m a t i o n From
one
form
to
the
other".
"The r e l a t i o n a l mode] and the"
[data
independent
accessing
mode]]
"appear
to
be c o m p l e t e l y at odds with
each
other"
"By
comparison,
the
d a t a - s t r u c t u r e - s e t mode] seems to be an
effective
hybrid
between
these
two
extremes".
J. Bradley, "An Extended O w n e r - C o u p l e d Set
Data
Model
and
Predicate
Calculus
for
Database
Management",
ACM
Trans.
on
Database
Syst., vol. 3, no. 4, Dec. 197~,
pp. 385-416.
R. Bell and P. M. D. Gray, " D e s c r i p t i o n of
Access
Paths for R e a l i s i n g R e l a t i o n s from
a
CODASYL
Database",
Research
Rep.
AUCS/TR-R~I,
Dept. of C o m p u t i n g Sci., U.
of A b e r d e e n , A b e r d e e n , UK, Jan. ]98~.
[In this data model,] "the logical v i e w
of
the
data
in
the
database
is
essentially
relational
but
with
the
superimposition
of
the
owner-coupled
set
concept".
"Extended
Bachman
d i a g r a m s in m o d i f i e d form can e a s i l y be
used
in
the
design
of
relational
"The
...
system
generates
Fortran
programs
to
retrieve
data
from
a
CODASYL
database
in
the
form
of
relations".
"The
system g e n e r a t e s an
internal
description
of
a
relation
called
a
'traversa]',
w h i c h includes
elements
representing
both
algebraic
o p e r a t o r s and C O D A S Y L DML c o m m a n d s " .
databases".
A. F. C a r d e n a s and M. H.
Pirahesh,
"Data
Base C o m m u n i c a t i o n in a H e t e r o g e n e o u s D a t a
Base
Management
System
Network",
I n f o r m a t i o n Syst., P e r g a m o n Press, Oxford,
UK, "~'?--~, no. l, 1980, pp. 55-79.
H. Biller, "On
the
Equivalence
of
Data
Base
Schemas
-A
S e m a n t i c A p p r o a c h to
Data
Translation",
Information
Syst.,
P e r g a m o n Press, Oxford, UK, v ol. a, no. I,
Iq79, pp. RS-4V.
"An a r c h i t e c t u r a l a p p r o a c h is
outlined
...
in
which
any user in any n e t w o r k
node can be
given
an
integrated
and
tailored
view
or
schema
(e.g.
hierarchical,
relational),
while
in
reality
the
data
may
reside
in one
single
data
base
or
in
physically
separated
data
bases,
managed
i n d i v i d u a l l y by the same type of
GDBMS
(e.g.
CODASYL,
IMS, relational) or by
different
GDBMS".
"The
entity-relationship
model
is
fundamentally
used
for
the
highly
logical
model layers of the i n t e g r a t e d
system".
[See also (Nahouraii, Brooks,
and C a r d e n a s , 1976)].
"The e q u i v a l e n c e of
data
base
states
and data base s c h e m a s is d e f i n e d " .
"It
is shown, h o w a s e m a n t i c d a t a model and
data
d e f i n i t i o n l a n g u a g e (LDDL) can be
used
to
construct
a
correct
specification
of
a
translation
function.
Finally, an e x a m p l e
of
the
translation
of
a
CODASYL
data
base
schema to a relational d a t a base schema
is given".
S. A. Borkin,
"Data
Mode]
Equivalence",
Proc.
4th
Intl. Conf. on V e r y Large Data
~ ,
r~, ~ p .
G. 4. C h a m p i n e , " C u r r e n t
Trends
Base Systems", C o m p u t e r , IEEE-CS,
no. S, M a y 1979, pp. 27-41.
r~v~, ~ . - ~ - ~ .
[This paper d e f i n e s
'data
'data
model
equiva]ence'.
(Borkin, 1979)].
model'
See
and
also
in
Data
vol. 12,
[In part
of
this
paper,
the
author
data
models
and
reviews
different
d e s c r i b e s s u p p o r t of m u l t i p l e m o d e l s on
one a r c h i t e c t u r e ] .
g. A. Borkin, " E q u i v a l e n c e
properties
of
Data
Models
for
Database
Semantic
gystems", Ph.D. thesis,
Dept.
of
Elect.
gng~n,
and
Computer
Sci.,
M.I.T.,
Cambridge,
MA,
Jan.
1979;
Lab.
for
Computer
Sci.
Tech.
Rep.
206;
NTIS
ADA055386;
slightly
revised
as
Data
Models:
A S e m a n t i c A p p r o a c h for D a t a b a s e
Systems,
M.I.T.
Press,
Camb~-dge,
MA,
198~.
P. P.-S.
Chen,
"The
Entity-Relationship
Mode]
-T o w a r d a Unified V i e w of Data",
Proc. [Ist] Intl. Conf. on V e r y Large Data
Bases, ACM, Sept. 1975, p. 173 (abstract);
ACM Trans. on D a t a b a s e Syst., vol. I,
no.
], Mar. 1976, pp. 9-36.
"A
data
model,
called
the
entity-relationship
model,
is
proposed".
[One section of
the
paper
d e s c r i b e s how] "the e n t i t y - r e l a t i o n s h i p
model
can
be
used
as
a basis
for
[This
thesis
defines
equivalence
of
models.
Motivations
include
m u l t i p l e data m o d e l s for one data base,
data
-
57
-
u n i f i c a t i o n of d i f f e r e n t views of data:
the
network
model,
the
relational
mode],
and
the
entity
set
model"
"Possible ways to derive their views of
data from the e n t i t y - r e l a t i o n s h i p mode]
are presented".
"General
purpose
support
for"
[non-programming]
"users
entails
p r o v i s i o n of an augmented
relationally
complete
retrieval
capability without
branching,
explicit
iteration,
or
cursors.
It
is
clear
how
this
c a p a b i l i t y can
be
realized
with
the
relational
approach".
"It
is not at
all clear how the n e t w o r k a p p r o a c h
can
reach
this
goal,
so
long
as
the
principal schema includes o w n e r - c o u p l e d
sets 'bearing i n f o r m a t i o n essentially'
A relational d i s c i p l i n e is s u g g e s t e d as
a way out for DBTG users".
Clemons,
"Design
of
a
Prototype
E. K.
A N S T / S P A R C T h r e e - S c h e m a Data Base System",
Proc. Nat]. C o m p u t e r
Conf.,
AFIPS,
vol.
~[~[, June 1979, pp. 689-696.
"This paper ... d e s c r i b e s
briefly
how
an
ANSI/SPARC
three-schema
data base
system p r o t o t y p e could be c o n s t r u c t e d " .
"For the internal level we propose that
a C O D A S Y L data base
management
system
be employed.
The conceptual level will
be a relational system".
E. K. Conoley, "Use of a H i e r a r c h i c a l Data
Model
to
Support
a Relational
Data
M a n a g e m e n t System",
M.A.
thesis,
U.
of
Texas,
Austin,
TX,
Aug.
1977;
NTIS
ADA047602.
L. Clough, W. D. Haseman, and
Y.
H.
So,
"Designing Optimal Data Structures", Proc.
Nat]. C o m p u t e r Conf., AFIPS, vol. 45, June
197~, pp. 829-R37.
[This
describes]
"a
relational
interface for i m p l e m e n t a t i o n as a front
end
to
a hierarchical
data
base".
"Relational o p e r a t i o n s were implemented
in terms of the a v a i l a b l e
hierarchical
DBMS functions".
"This
paper
is
concerned
with
developing
a m e t h o d o l o g y for d e s i g n i n g
optimal network data base
structures".
[Data d e s c r i p t i o n begins in the form of
networks,
which
are
converted
into
hierarchies,
then into relations, then
into canonical
networks,
and
finally
into opt~ma] networks, based upon] "the
set of queries," [using] "an o p e r a t i o n s
research
mode]"
[See
also
(De,
Haseman,
and
Kriebel,
1978)
and
(Haseman and Whinston, ]Q77)].
C.
J.
Date,
"An
Architecture
for
High-Level
Language D a t a b a s e E x t e n s i o n s " ,
Proc. A C M - S I G M O D Intl. Conf. on M a n a g e m e n t
of Data, June 197~, pp. 1@1-122.
"The p r o g r a m m e r is p r o v i d e d
with
the
ability
to
handle
all
three
of the
well-known
database
structures
(relational, h i e r a r c h i c a l , n e t w o r k ) , in
a single
integrated
set
of
language
extensions".
"A
database
is
represented, not as some
new
kind
of
input/output
file,
but instead simply
as
part
of
the
program's
directly
addressable
storage
area"
[See also
(Date, 1977) and (Date, 1980)].
E.
F.
Codd,
"A
Data
Base
Sublanguage
Founded on the Relational Calculus", Proc.
1971
ACM-gIGF!DET
[SIGMOD]
Workshop
on
Data
D~c#iption,
Access,
and
Control,
Nov. l~ff, pp. 35"6R;
IBM
Research
Rep.
RJ 89~ ({15716), July 1971.
"Three principal types of l a n g u a g e
for
data
base m a n i p u l a t i o n are identified:
the
low-level,
procedure-oriented
(typiFied by the C O D A S Y L - p r o p o s e d DML),
the
intermediate
level,
algebraic
(typiFied
by
Project
MAC
MacAIMS
language),
and
the
high
level,
relational
calculus-based
data
sub]anguaqe, an
example
of
which
is
described".
"Arguments
are p r e s e n t e d
for
the
superiority
of
the
calculus-based
type
of
data
base
s u b S a n q u a g e over the a]gebraic, and for
the
algebraic
over
the
low-Revel
C. J. Date, An
Introduction
to
Database
Systems, 2nd ed., A d d i s o n - W e s l e y , Reading,
MA, 1977, Chap. 25 ("The Three
Approaches
Revisited") , pp. 425-461.
[One section of this chapter d e f i n e s
a
language
based
upon (Date, 1976).
In
another section, the author a r g u e s that
the
relational
model
is simpler, and
has a firmer theoretical base, than the
C O D A S Y L model.
See also (Date, 1980)].
C.
J.
Date,
"An
Introduction
to
the
Unified
Database
Language
(UDL)", Proc.
6th Intl. Conf. on V e r y Large Data
Bases,
ACM, Oct. 1980, pp. 15-32.
procedural"
E. F. Codd and C.
J.
Date,
"Interactive
Support
for
Non-Programmers:
The
Relational
an~
Network
Approaches",
in
(Rust~n,
!974),
pp. ]1-4];
IBM R e s e a r c h
Rep. RJ ] 4 ~
(~21~38) , June 1974.
"The first d e s c r i p t i o n of UDL was g i v e n
in" [(Date, 1976)].
"The present paper
p r o v i d e s an
informal
introduction
to
the
concepts
and f a c i l i t i e s of UDL as
c u r r e n t l y d e f i n e d ..., and thus forms a
-
58
-
rep3acement
for
[See also (Date,
the
original
Iq77%].
interfaces
relational,
models".
paper".
C..7. Date and E. ~. Codd, "The Relational
and Network Approaches:
C o m p a r i s o n of the
Application
Programming
Interfaces",
in
(Rustin,
Iq74), pp. 83-I13;
IBM R e s e a r c h
Rep. RJ 14~l ( ~ ] 7 S 6 ) , June 1974.
of
Data
Data Base
Symp.
6,
Englewood
[This paper c o m p a r e s
data
base
usage
at]
"three
levels
of
d e s c r i p t i o n of
data
structures":
"(i)
The
implementation
level or m a c h i n e level,
(2) A logical (semantic) level in which
access
paths are specified explicitly,
and (3) A logical level in which
only
the
relationships
between
data items
are specified".
[The second
level
is
not s p e c i f i c a l l y CODASYL].
P. De, W. D. Haseman, and C.
H.
Kriebel,
"Toward
an
Optimal
Design
of a N e t w o r k
Database
From
Relational
Descriptions",
Operations
Research,
Operations Research
$oc. oF ~ e r i c a ,
Baltimore, MD,
vol.
26,
no. 5, Sept.-Oct. 1978, pp. e@5-823.
C.
P.
Earnest,
"A
Comparison
of
the
Network
and
Relational
Data
Structure
Models",
Computer
Sciences
Corp.,
E1
Segundo, CA, Apr. 1974.
"This paper a t t e m p t s to bring
out
the
similarities
and
d i f f e r e n c e s clearly,
by d e f i n i n g and d i s c u s s i n g both
models
on
a common
basis
of
terminology".
"Major c o n c l u s i o n s are that (i) the two
models
are
in
practice
not
very
different,
(2)
the
relational
structures
are
somewhat
simpler than
networks, but (37 the price for this is
that
the
network
model
has
more
structural power, and more,
not
less,
d a t a i n d e p e n d e n c e than the relational".
"This
paper
suggests
a method
for
building up a network d a t a b a s e starting
from
relational
descriptions.
The
network
generated
is optima] in terms
of d a t a
item
appearances
and,
given
that,
it
is also optimal in terms of
the number of records".
"Some
of
the
concepts
...
are
extensions
of
the
ideas" [in (Clough,
Haseman,
and
So,
79~6~
and
(Haseman
and
Whinston,
1977) ] .
"A
Canonical
Schema
for
a
Data
Mode]
With
Local
Computer J., British Computer
23,
no. --3, Aug.
198g, pp.
C. P. Earnest, " S e l e c t i o n and Higher Level
Structures
in Networks", B. C. M. Douqu~
and
G.
M.
Nijssen
(Eds.),
Data
Base
Description
(Proc.
IFIP
TC-2
spec-~T
W o r k i n g Conf. on
Data
Base
Description,
Jan.
1975),
North-Holland,
Amsterdam,
Neth., 1975, pp. 215-237.
"A global
schema
is
proposed
for
a
g e n e r a l ~ s e d data base system capable of
supporting interfaces to other
systems
-notably
Relational,
Codasyl
and
Adabas
-through
appropriate
local
schemas
and
data
manipulation
languages.
The proposed global
schema
consists
of
entries
in
the
form of
normalised relations".
"We
have
shown
how
to
superimpose
higher
level s t r u c t u r e s on the records
and
record
interconnections
of
a
database,
and
how
to
use
these
structures
for
data
selection
and
manipulation".
R. El-Masri and G. W i e d e r h o l d , " P r o p e r t i e s
of
Relationships
and
their
Representation",
Proc.
Natl.
Computer
Conf.,
AFIPS,
vol.
49,
May
1980,
pp.
319-326.
A.
Dogac
and
E.
A.
Ozkarahan,
"A
~eneralized
DBMS
Implementation
on
a
Database Machine", Proc.
ACM-SIGMOD
Ig80
Intl.
Conf.
on
Management
o ~ Data, May
p~T--l'i~3-r~'~.
of
the
hierarchical
J.
Earley,
"On
the
Semantics
Structures",
R.
Rustin
(Ed.),
Systems (Courant Computer
Sci.
May
1971),
Prentice-Hall,
Cliffs, NJ, 1972, pp. 23-32.
"The purpose o f this paper is
to
give
some
comparisons
between
these
two
approaches
(primarily
from
the
application
programming
viewpoint)"
"We now p r e s e n t a d i s c u s s i o n of what we
consiaer
to be the relative a d v a n t a g e s
of the relational approach,
under
the
fol]owing
headings:
simplicity,
uniformity,
completeness,
data
independence, integrity and security".
S. M. Deen,
Generalised
Interfaces",
Soc.,
vol.
~l-2S~.
consisting
network,
and
""
"We examined the semantic p r o p e r t i e s of
a
relationship
between
two
entity
classes".
"We compared six data m o d e l s
with
respect to the c h o i c e s they offer
for
the
representation
of
relationships".
"The d e s i g n
and
implementation
of
a
generalized
d a t a b a s e m a n a g e m e n t system
based on the RAP
database
machine
is
described"
"The
E/R mode] is chosen
as
the
Meta
Data
Model
(Conceptual
Schema)
which g e n e r a t e s external model
-
59
-
R. Gerritsen, "A
Preliminary
System
for
the D e s i g n of DBTG Data Structures", Proc.
A C M - S I G M O D Inltl. Conf.
on
Management
of
Data•
May
"I~75,
p.--16~----~as~ct)-;~un.
ACM, vol. 18, no. 10,
Oct.
1975,
pp. 551-557.
G.
C.
Everest•
"Basic
Data
Structure
Mode]s
Exp]ained
With a Common Example",
Proc.
Fifth
Texas
Conf.
on
Computing
~s.,
"l~'gfgfrCS,---~. lrg77C~p~. 3gza6 '.
"This
paper
presents
a
taxonomy
of
basic
data
structures
which
cuts
through
and
omits
the
secondary
differences
to
highlight
the
most
important logical
differences".
"The
essential
characteristics
of
each of
... six basic d a t a s t r u c t u r e m o d e l s are
d e s c r i b e d and each ~s e x e m p l i f i e d using
a
common
example".
[See
also
(Auerbach, I9~g)].
[This is based upon (Gerritsen,
See also (Gerritsen, 1975b)].
R. G e r r i t s e n , "The Relational and
Network
Models
of Data Bases:
B r i d g i n g the Gap",
Proc. 2nd
USA
- Japan
Computer
Conf.,
AFIPS, Aug. 1975, pp. 347-351.
"An attempt is m a d e to lay to rest
the
question
of
supremacy
of
either the
n e t w o r k or the relational model of data
bases.
It
is
argued
that these two
models
correspond
to
two
distinct
levels of d e s c r i p t i o n ;
a relational or
n o n - p r o c e d u r a l level and an access path
level.
Hence,
a translation approach
is
suggested
whereby
relational
descriptions
can
be
translated
to
network
descriptions".
[See
also
(Gerritsen,
1975a)
and
(Gerritsen,
1975c)].
E.
Fa3kenberg,
"Concepts
for
the
Coexistence
Approach
to
Data
Base
Management",
E.
Morlet
and
D.
Ribbens
(Eds.} ,
Intl.
Computing
Symp.
1977,
North-Hollan~,
Amsterdam,
Neth.,
Ap~]
19~7, pp. 39-5~.
"The
idea
providing
coexistence
of
various
data
models
and
data
manipulation methods
within
one
data
base
management
system
imposes
new
requirements
on
the
design
of
such
systems".
"As
a common basis for any
external or internal interface, the use
of
a
s e m a n t i c a l l y c o m p l e t e and unique
form of d a t a - - the d e e p
structure
of
data
-at
the
central interface is
suggested".
"Transformations
from
a
deep
structure
into
various
semantically
equivalent
surface
structures
of
data ~
[(CODASYL
and
re]at~onal}]
"are shown".
R.
Gerritsen,
Structures",
Ph.D.
Industrial
Admin.,
Pittsburgh,
PA,
ADA00R937.
"Understanding
Data
diss., Grad. School of
Carnegie-Mellon
U.•
Feb.
1975;
NTIS
[The
system
described
herein]
" g e n e r a t e s a DDL d e s c r i p t i o n from a set
of
queries"
[expressed
in
HI-IQ
(a
not-exactly-relational
language), based
upon] "data
relationships
implied
by
the
queries".
[The
system
also]
" t r a n s l a t e s a q u e r y to COBOL
procedure
augmented
by
Data
Manipulation
Language".
[gee
also
(Gerritsen,
1975a) and (Gerritsen, 1975b)].
M. Fleck, "On the E q u i v a l e n c e of Data Base
Models"
Tech
Rep.
TR
25.14a,
IBM
L a b o r a t o r y , Vienna, Austria, J u l y 1975.
"The
equiva]ence
problem
between
different
data
models
of a data base
system is investigated.
The n o t i o n s of
data-equivalence
and
consistency-equivalence
are introduced.
A
specific
solution
to
gain
consistency-equivalence
is
proposed
where the n e c e s s a r y c h a n g e s of the d a t a
models
are
minima]"
"This
report"
[uses]
"the
relational
mode] ... and
the Codasyl DBTG model"
J.
Goldman,
"Automated
Generation
of
Relational S c h e m a s for C O D A S Y L D a t a b a s e s " ,
S p e r r y R e s e a r c h Center Rep.
SRC-RP-79-13,
Sudbury, MA, Mar. 1979.
"A f a c i l i t y
which
translates
CODASYL
database
schemas
into
relational
d a t a b a s e schemas is d e s c r i b e d " .
"The
d e r i v e d relational schema p r e s e r v e s the
i n f o r m a t i o n c o n t e n t of the d a t a b a s e and
would
support
high
level
data
sublanguage
access
to
the
database,
both
retrieval and update".
[See also
(Zaniolo, 1979a) , (Zaniolo, 1979b) , and
(Zaniolo, 1977)].
J.
P. Fry and E. H. Sibley, " E v o l u t i o n
of
Management
Systems", C o m p u t i n ~
Surveys, ACM, vol. R, no.
l,
Mar.
197g,
pp. 7-42.
Data-Base
[One section b r i e f l y d e s c r i b e s
data
mode]s
and
compares
terminologyJ.
1975c) .
several
their
D.
Goldschmidt
and
A.
Reiter,
"An
Implementation
of
FORAL
Using IDMS", B.
S h n e i d e r m a n (Ed.% , Databases:
Improving
Usability
and R e s p o n s i v e n e s s - ( P r o c .
[n{~.
Conf. on D a ~ ' ~ a s ~ :
Improving
Usability
-
60
and
Responsiveness,
Press, N e w York, NY,
Aug.
1978,
1978), A c a d e m i c
pp. iqi-150.
J. Iossiphidis, "A T r a n s l a t o r
to
Convert
the DDL of ERM to the DDL of System 2@00",
P. P.-£. Chen (Ed.) , Proc. Intl. Conf.
on
Entity-Relationship
Approach
to
Systems
~n~---F~6rg 5, Dec.
T~79,
pp.
An~ysls
~50-57~;
later
published
as
Entity-Relationship
Approach
to
Systems
Analysis
and
Design,
North-Holland,
"PORAL
is
a
non-procedural
data
s p e c i f i c a t i o n and m a n i p u l a t i o n l a n g u a g e
based on b i n a r y a s s o c i a t i o n s .
IDMS
is
a commercial d a t a b a s e m a n a g e m e n t system
based
on
a
'network'
model
and
belonging
to the C O D A S Y L DBTG g r o u p of
languages.
We
describe
an
i m p l e m e n t a t i o n of a subset of the FORAL
query
language
over
existing
IDM£
"This
paper
describes
ERL
a
nonprocedural
data d e f i n i t i o n language
(DDL) for the e n t i t y r e l a t i o n s h i p model
(ERM) of a data base m a n a g e m e n t system.
Also d e s c r i b e d is the translator
built
to c o n v e r t ERL p r o g r a m s into the DDL of
SYSTEM 2 ~ 0 "
databases".
W. T. H a r d q r a v e and E.
H.
Sibley,
"Data
Model
Processing:
An
Approach
to
Standardization
of
Database
Management
Systems",
Tech.
Rep.
45, Dept. of Info.
Syst. Management, U. of Maryland,
College
Park, MD, J u l y 1979.
H. R. J o h n s o n
and
J.
A.
Larson,
"Data
Management
for
Microcomputers",
Proc.
C O M P C O N Fall 79, IEEE-CS, Sept. 1979,
pp.
191-194.
"This
paper
outlines
a
general
philosophy
and
framework
for
the
specification
of
a
data
model.
Extracts
from scenarios that have been
d e v e l o p e d for s p e c i f i c a t i o n of
several
well-known
data
models
(e.g.,
DBTG,
relational,
TDMS~
are
given
and
discussed"
"The
scenarios
are
intended
for
implementation
of
an
augmented
positional
processor
that
will be able to support d i f f e r e n t
data
models".
[See
also
(Rothnie
and
Hardgrave, 1976)].
[This is similar to
(Johnson,
Larson,
and
Lawrence,
1979).
See
also
(Johnson, Larson, and
Lawrence,
1978)
and
(Larson,
Johnson,
and
Lawrence,
1978)].
H. R. Johnson, J. A.
Larson,
and
J.
D.
Lawrence,
"Network
and
Relational
Modelling
in
a
Common
Data
Base
Architecture
Environment",
Sperry Univac
Research
Rep.
TMA~720,
Roseville,
MN,
Mar. 1979.
W.
D.
Haseman
and
A.
B.
Whinston,
Introduction
to
Data Management, Richard
~-rwln,~me~odT--TL,
I~77,
Chap.
15
{"Designing Optimal D a t a Structures"~ , pp.
"A common data
base
architecture
and
its
a p p l i c a t i o n s in supporting v a r i o u s
l a n g u a g e file
systems
and
data
base
management
systems
are
described".
"Data base m a n a g e m e n t s p e c i f i c a t i o n s of
197£
CODASYL
Journals
of D e v e l o p m e n t
and
of
SEQUEL
2
are
extended".
" I n f o r m a t i o n preserving t r a n s f o r m a t i o n s
b e t w e e n s u b m o d e l s within and across the
models
are
specified".
[See
also
(Johnson and Larson,
1979),
(Johnson,
Larson,
and
Lawrence,
1978),
and
(Larson, Johnson, and Lawrence, 1978)].
[mhis is similar to
(Clouqh,
Haseman,
and
So, 1976).
See also (De, Haseman,
and Mriebe], 197£%].
B. C. Housel,
Manipulation
Rierarchical,
IBM
Research
19"79.
"QUEST:
A
High-Level
Data
Language
for
Network,
and
Relational
Databases",
Rep.
RJ 25£8 {~348£), J u l y
H. R. Johnson, J. A.
Larson,
and
J.
D.
Lawrence, " T r a n s f o r m a t i o n s Between N e t w o r k
and Relational Data Models", Sperry Univac
Research
Rep.
TMA00729,
Roseville,
MN,
Mar. 1978.
"This paper d e s c r i b e s a query language,
QUEST,
which
provides
a
single
interface
to
the
three
major
data
models.
The
initial
d e v e l o p m e n t was
aimed
at
providing
a
simple
but
powerful
high-level
interface
for
network
databases.
Subsequently,
however,
it Proved s t r a i g h t f o r w a r d to
extend the s e m a n t i c s
in
a consistent
way
to
include
the
h i e r a r c h i c a l and
relational models".
-
[This paper
describes
algorithms
for
translation
(in
both
directions)
between
"minimally
keyed"
network
schemas
and
"fully
keyed"
network
schemas,
and
between
fully
keyed
network schemas and relational schemas.
See also (Johnson
and
Larson,
1979),
(Johnson,
Larson, and Lawrence, 1979),
and
(Larson,
Johnson,
and
Lawrence,
197R)].
61
-
S.
R.
Kimbleton
and
P.
S.-C.
Wang,
" A p p l i c a t i o n s and Protocols", to appear in
M. Paul
and
H.
J.
Siegert
(Eds.),
An
Advanced
Course on D i s t r i b u t e d Systems -Architecture
any
Imp~ementat[on,
Springer-Verlag, N~-York,
MY, 1980.
L.
A.
Ka] inichenko,
"Data
Models
Transformation
Method
Based on A x i o m a t i c
Data Model
Extension",
Proc.
4th
Intl.
Conf. on v e r y Large D a t a Bases, ACM, Sept.
"This work c o n c e n t r a t e s on the
problem
of
incompatible
data
models
transformation,
the
criteria
of
correctness
of
such
transformations,
and m e t h o d s of c o n s t r u c t i o n of
correct
transformations
being
defined".
[See
also (Ka]inichenko, 1q76)].
"Accessing
multiple,
heterogeneous,
remote
Database
Management
Systems
p r o m i s e s to
be
difficult
because
of
differences
in:
i)
the
data
model
employed,
ill
data
structures
c o n s t r u c t e d using this data model, iii)
Database
Management
System
functionality
differences,
iv)
differences
in
Data
Manipulation
Languages
used in interacting with the
data structures, and v) c o m p u t e r system
differences.
Imposing
a u n i f o r m user
viewpoint
across
this
collection
of
differences
is
an
alternative
to
requiring d e t a i l e d
user
knowledge
of
the
characteristics
of
each
of
the
accessed
systems".
[See
also
(Kimbleton, Wang, and Fong, 1979)].
L.
A.
~a]inichenko,
"Relational-Network
Data
gtructure
Mapping",
G.
M. N i j s s e n
(Ed.} , M o d e l l i n g in Data
Base
Management
Systems-'-T~'--IIFT'P--~C2
~ing
Conf. on
M o d e l l i n g in Data Base
Management
Syst.,
Jan.
197~),
North-Holland,
Amsterdam,
Neth., Ig~6, pp. ~ 3 - ~ 0 9 .
"Mapping
is
considered"
[between]
"n-ary relations" [and] "network data".
[~ee also (~alinichenko, 197~)].
S. R. Kimbleton, P. S.-C. Wang, and E.
N.
Fong, "XNDM=
An E x p e r i m e n t a l N e t w o r k Data
Manager",
Proc.
4th
Berkeley
Conf.
on
Distributed
Data
M a n a g e m e n t and C o m p u t e r
N e t w o r k s , NTIS, Aug. 1979, pp. 3-17.
M. H. ~ay, "An A s s e s s m e n t o f
the
CODASYL
DDL
for Use With a Relational S u b s c h e m a " ,
B. C. M. Douqu6 and G. M. N i j s s e n
(Eds.) ,
Data
Base
Description
(Proc.
IFIP TC-2
p ~ i aT---Wo rl ~ q - - - i ~ n6~['?
on
Data
Base
Description,
Jan.
]g~5),
North-Holland,
A m s t e r d a m , Neth., 1975, pp. 199-214.
"This paper
describes"
[a]
"research
p r o j e c t c o n c e r n e d with e s t a b l i s h i n g the
feasibility, issues, a l t e r n a t i v e s ,
and
a
technical
a p p r o a c h for s u p p o r t i n g a
network
data
manager".
"The
basic
a s s u m p t i o n underlying the d e s i g n ... is
heterogeneity
of
data
models,
data
structures,
DBMSs,
DMLs
and c o m p u t e r
systems on which these
DBMSs
reside".
[The
paper describes]
"superimposing a
uniform
user
viewpoint".
[See
also
(Kimbleton and Wang, 1980)].
"This
paper
investigates
the
possibi]ity
of
accessing
a
DDLC
database described
by
a DDLC
schema
t h r o u g h a subschema p r e s e n t i n g the user
with
a
relational
view
of
the
database".
"The a r g u m e n t will proceed
by first d e s c r i b i n g some
of
the
ways
relations
might
be
based
on n e t w o r k
s t r u c t u r e s yielding c o n s i s t e n t
effects
on
retrieval,
and by then c o n s i d e r i n g
for each of
these
'derivation
rules'
the effect of updating a relation".
A. C. Klug, " T h e o r y of D a t a b a s e M a p p i n g s " ,
Ph.D.
thesis,
Dept. of C o m p u t e r Sci., U.
of Toronto, Toronto,
Ont.,
Canada,
Dec.
197g;
C o m p u t e r Syst. R e s e a r c h G r o u p Tech.
Rep. 98.
L. ~erschberg,
A.
C.
~lug,
and
D.
C.
Tsichritzis,
"A T a x o n o m y of D a t a Models",
P. C. L o c k e m a n n and E. J. N e u h o l d
(Eds.% ,
Systems
for
Large
Data Bases (Proc. 2nd
"T'nt~f'~'-'Y~on~. on
Very
Large
Data
Bases,
SePt.
1976),
North-Holland,
Amsterdam,
Neth., 1q77, pp. 43-~4.
" D e f i n i t i o n s of s t r u c t u r e and o p e r a t i o n
mappings
are given".
[Mappings can be
between
schemas,
between
schema
and
subschema, b e t w e e n data models, b e t w e e n
levels (e.g., logical and p h y s i c a l ) , or
between
multiple-node
and s i n g l e - n o d e
q u e r i e s in a d i s t r i b u t e d d a t a base].
"This paper c l a s s i f i e s a c o l l e c t i o n
of
conceptual
data
models
within
a
taxonomy framework
consisting
of
the
fo]]owing
parameters:
graph theoretic
versus
set
theoretic
models,
mathematical
foundations, t e r m i n o l o g y ,
and semantic levels of a b s t r a c t i o n " .
A.
C.
Klug
and
D.
C.
Tsichritzis,
"Multiple
View
Support
Within
the
ANSI/SPARC
Framework",
Proc.
3rd
Intl.
Conf.
on V e r y Large Data'-~'~s,--A~M,-'~c ."
" F e a t u r e s for the conceptual mode]
are
discussed".
[This
is based upon the
language
described
in
(Tsichritzis,
-
62
-
part of
the
compiler".
[The
latter
language
can
use
tuple-at-a-time
access, as d o e s the C O D A S Y L
DML.
See
also (Astrahan et al., Ig76)].
1975%].
"Three
external
models
corresponding
to
the
hierarchical,
network
and
relational
approach
are
mapped
onto
the
conceptual
model"
[See
also (gchmid and B e r n s t e i n , 1975)
and (Tsichritzis, 1975)].
J. R. Lucking, " C o m m e n t s on A d v a n t a g e s
of
the Data S t r u c t u r e Set Model", in (Rustin,
1974), pp. 115-119.
J. A. Larson, H. R.
Johnson,
and
J.
D.
Lawrence,
"Multimodel
Data
Base
M a n a g e m e n t " , S p e r r y Univac
Research
Rep.
T M A S S 7 3 1 , R o s e v i ] l e , MN, Oct. 197R.
"At the d e c l a r a t i v e level of d e s c r i b i n g
data,
there is v i r t u a l l y no d i f f e r e n c e
b e t w e e n n e t w o r k s and relations.
At the
manipulative
level,
the
comparisons
that
we
have
seen
today
have
been
slightly
unfair,
in
that
one
is
compar ins
systems
of
a
sl ightly
different
level of p r o c e d u r a l i t y .
The
constraints
imposed
upon
DBTG
in
defining
language
are the c o n s t r a i n t s
imposed by COBOL".
"An
intermediate
data
model
is
described
which
acts
as
a
stepping
stone to b r i d g e the d i f f e r e n c e s b e t w e e n
CODASYL
and
relational
data
models.
Information preserving
transformations
are d e s c r i b e d w h i c h m a y be m e c h a n i c a l l y
data
applied
to
data
definition
or
manipulation
statements
of
one
data
mode] to o b t a i n
equivalent
statements
Using these
in
the
other d a t a model.
transformations
it
is
possible
to
d e s i g n a multimode] DBMS w h i c h s u p p o r t s
both
network
and
relational
data
mode] s".
[See
a] so
(Johnson
and
Larson, 1979~ ,
(Johnson,
Larson,
and
Lawrence,
1979), and (Johnson, Larson,
and Lawrence, I ~ ) ] .
W. C. McGee, "A C o n t r i b u t i o n to the
Study
of Data E q u i v a l e n c e " , J. W. K l i m b i e and K.
L. M o f f e m a n (Eds.) , Data
Base
Management
(Proc.
IFIP
TC-2
Working
Conf. on Data
Base
Management,
Apr.
1974),
N o r t h - H o l l a n d , A m s t e r d a m , Neth., 1974, pp.
12~-148.
"The paper p r e s e n t s a set of t e c h n i q u e s
for
transforming
structures
of
one
p a r t i c u l a r " "data s t r u c t u r e
class
(or
DSC)"
"into e q u i v a l e n t s t r u c t u r e s of a
second DSC.
As the first DSC, we
will
take
the
Flat
Data S t r u c t u r e Class".
"As the second DSC, we
will
take
the
class
implicit in the data d e s c r i p t i o n
language
of
the
CODASYL
Data
Description Language Committee".
R. M. Lee, " C o m p a r i s o n of
HI-TQ
and
the
Relational
Calculus",
Dept.
of D e c i s i o n
Sciences
working
paper
7R-~7-~5,
the
Wharton
School,
U.
of
Pennsylvania,
P h i l a d e l p h i a , PA, J u l y 1978.
"Paper
compares
the
retrieval
c a p a b i l i t i e s of HI-IQ, a n o n - p r o c e d u r a l
query
language
for
Network
type
d a t a b a s e s , to the R e l a t i o n a l C a l c u l u s " .
W. C. McGee, "On User
Criteria
for
Data
Model
E v a l u a t i o n " , ACM Trans. on D a t a b a s e
Syst., vol.
I,
no.----~,--EfEZ -T97E,
pp.
R. M. Lee, "A Short S u r v e y of C u r r e n t D a t a
Models",
Dept.
of
Decision
Sciences
working
paper
7R-S2-~7,
the
Wharton
School,
U. of P e n n s y l v a n i a , P h i l a d e l p h i a ,
PA, Feb. lqTR.
TTE:7s7.
"An
evaluation
procedure
is
needed
which
will
a l l o w the user to e v a l u a t e
a l t e r n a t i v e m o d e l s in the c o n t e x t of
a
specific
set
of
applications".
"Two
kinds of c r i t e r i a are
presented:
use
criteria,
which
m e a s u r e the u s a b i l i t y
oF
the
mode];
and
implementation
criteria,
which
measure
the
i m p l e m e n t a b i l i t y of the mode]
and
the
efficiency
of
the
resulting
implementation.
The
use
of
the
criteria
is
illustrated
by
applying
them
to
three
specific
models:
an
n-ary
relational
model,
a hierarchic
model, and a n e t w o r k model".
"This paper p r e s e n t s a b r i e f
tutorial
on
several
of
the m o r e p o p u l a r 'data
models' or logical r e p r e s e n t a t i o n s used
in d a t a b a s e s y s t e m s to c h a r a c t e r i z e the
structural a s p e c t s of the d a t a b a s e " .
R. A. Lorie and J. F. Nilsson, "An
Access
Npecif~cation
Languaqe
for
a Relational
Data Base System",
IBM
J.
Research
and
D e v e l o p m e n t , vol. 23~'--~o.-n[, ~y~'3-g~T~, E .
2~5-29R.
"We a d d r e s s the
problem
of
executing
high
level
language queries submitted
to a relational data base system.
As a
step
in the p r o c e s s of c o n s t r u c t i n g an
'efficient' c o m p i l e r for a high
level
language
we suggest the e l a b o r a t i o n of
an i n t e r m e d i a t e level
language
acting
as
a target l a n g u a g e for the o p t i m i z e r
-
L.
I.
Mercz,
"Issues
in
Building
a
Relational
Interface
on a C O D A ~ Y L DAMS",
G. Bracchi and G. M. N i j s s e n (Eds.) , Data
Base A r c h i t e c t u r e (Proc. IFIP TC-2 Wor]EEEg
Data
Base
Architecture,
June
Conf.
on
197Q),
North-Holland,
Amsterdam,
Neth.,
63
1979,
pp.
record types (which m a y
be
a
set
of
files
from
a
file
system
or record
types / s e g m e n t s
in
a
DBMS)
into
a
n u m b e r of r e l a t i o n s " .
191-~II.
"The C O D A S Y L ' V e d a t a b a s e p r o p o s a l s
are
evaluated
a n d found to be i n s u f f i c i e n t
For p r o v i d i n q a s e m a n t i c a l l y
complete,
Formal
description
for the c o n c e p t u a l
schema.
T h e r e f o r e , it is not
possible
to
derive
a
c o m p l e t e relational v i e w
from a C O D A S Y L
schema.
In
contrast
with
the
CODASYL'7R
proposals,
a
p r o c e d u r a l external schema and
related
manipulation
operators
are
data
outlined,
which
can
coexist
with
n o r m a l i z e d relational v i e w s on the same
i n f o r m a t i o n base".
E.
J.
Neuhold,
"Data
Mapping:
Formal
Hierarchical
and
Relational
Model",
R.
R u s t i n (Ed.) , Data Base
Systems
(Courant
Computer
Sc[.
Symp.
6,
May
1971),
P r e n t i c e - H a l l , E n g l e w o o d Cliffs, NJ, 1972,
p.
185
(abstract);
"Data
Mapping:
A
Formal H i e r a r c h i c a ] and R e l a t i o n a l
View",
Institute
For
Appl.
Informatics,
U. of
Karlsruhe,
Karlsruhe,
W.
Germany,
Feb.
1973.
A. ~. M i c h a e l s ,
B.
Mittman,
and
C.
R.
Carlson,
"A
C o m p a r i s o n of the R e l a t i o n a l
and
CNDASYL
Approaches
to
Data-Base
Management",
C o m p u t i n g Surveys, ACM, vol.
~, n o . I, Mar. ]97~, pp.--~'~-~-CT~l.
"The
techniques
developed
for
the
formal
description
of the s e m a n t i c of
p r o g r a m m i n g l a n g u a g e s can be a p p l i e d to
the
d i f f e r e n t d a t a c o n s t r u c t s found in
data
base
systems".
"This
paper
concentrates
on
hierarchical
o r g a n i s a t i o n s ..., and c o m p a r e s some of
their p r o p e r t i e s to the r e l a t i o n a l v i e w
of data".
"Data
definition,
manipulation,
protection,
and
independence,
and
system
performance
are
important
factors
when
studying
and e v a l u a t i n g
data-base
management
systems".
"The
relational
and
C O D A e Y L Data Base Task
G r o u p a p p r o a c h e s ... are
compared
and
contrasted
from
these p o i n t s of view.
The
paper
concludes
with
the
observation
that
since
data-base
manaqement systems
are
to
serve
the
needs
of w i d e l y d i v e r s e c o m m u n i t i e s of
users, no single a p p r o a c h to
data-base
management
seems
either
d e s i r a b l e or
l i k e l y to e m e r g e
as
dominant
in
the
near Future".
G. M. N i j s s e n , "Data
Structuring
in
the
DDL
and
R e l a t i o n a l Model", J. W. K l i m b i e
and
K.
L.
~offeman
(Eds.) , Data
Base
Mana g e m e n ~
(Proc. IFIP TC-2 W o r k i n g Conf.
on
Data
Base
Management,
Apr.
1974),
N o r t h - H o l l a n d , A m s t e r d a m , Neth., 1974, pp.
363-384.
of
"The m a i n data s t r u c t u r i n g e l e m e n t s
the
CODASYL
DDL
and
R e l a t i o n a l Data
Model are c o m p a r e d .
The c o m p a r i s o n
is
illustrated
with
an
e x a m p l e and some
data d e s c r i p t i o n s .
The m a i n c o n c l u s i o n
is
that
a
common
DDL
could
be
specified,
encompassing
the
main
aspects
of
the
CODASYL
DDL
and
Relational
Data
Model.
An
instant
guideline
for
DDL
users"
[for
relational-like
use]
"and
some
DDL
modifications
are
also
shortly
described".
E. N a h o u r a i i , L.
O.
Brooks,
and
A.
F.
Data
Cardenas,
"An
Approach
to
Communication
Between
Different
G e n e r a l i z e d Data Base M a n a g e m e n t ~ y s t e m s " ,
P. C. L o c k e m a n n and E. J. N e u h o l d
(Eds.) ,
Systems
For
Larqe
Data B a s e s (Proc. ~nd
Intl. ConT.
on ~ r y
Larqe
Data
Bases,
qeDt.
1q~6) , N o r t h - H o l l a n d ,
Amsterdam,
Neth., lg~7, pp. 1 1 7 - I ~ .
T. W. Olle, The C O D A S Y L A p p r o a c h
to
Data
Base
Management, Jo n~W~y
and Sons, N e w
~r~'~]~, NY,
I-~T~[, Chap.
24
("Relational
A p p r o a c h " ) , pp. 266-279.
"mbis
report
discusses
some
of
the
p r o b l e m s and p r o v i d e s a m e t h o d o l o g y For
communicating
and
exchanging
information
between
heterogeneous
data
or
DBMSS
that
are
models
of
commercially available".
"Our p r o p o s e d
approach
to
interconnecting
heteroqeneous
DBM~s is to c h a r a c t e r i z e
the a c c e s s p a t h s into and
through
the
data
in
a DIAM string c a t a l o g " .
[See
also (Cardenas and P i r a h e s h , 19~@)].
[This c h a p t e r d e f i n e s
of
the
relational
compares
them
with
CODASYL
data
model.
1975)].
T. W. Of]e, " C u r r e n t and F u t u r e T r e n d s
in
Data
Base M a n a g e m e n t S y s t e m s " , Proc. IFIP
Congress
74,
North-Holland,
A~T~Fr a~,
Net-~., Aug. 1974, pp. 9 9 R - 1 0 0 6 .
S. R. N a v a t h e , "An I n t u i t i v e
Approach
to
Normalize
N e t w o r k S t r u c t u r e d Data", Proc.
Bases,
6th Intl. Conf. on v e r y Large Data
[This
paper
describes]
procedure
For
converting
various
aspects
data
model
and
aspects
of
the
See also (Olle,
[Tn part of this paper], "the
work
of
the C O D A S Y L Data Base Task G r o u p and of
the g r o u p s
which
it
has
spawned
is
"a
simple
a n e t w o r k of
-
64
-
o~
data m o d e l s " .
[See also
and Sibley, 1979)].
compared
with
that of the G u i d e - S h a r e
g r o u p s and with the
emerging
theories
on
relational
data
bases.
The
s i g n i f i c a n t features of C o d d ' s work are
selected
and
their
potential
impact
assessed".
(Hardgrave
J. B. R u b y and A. G. C a r r i c k , "An A p p r o a c h
to
Providing a Re]ationa] Query Processor
for a Limited C O D A S Y L Data Base M a n a g e m e n t
System",
Proc.
3rd
USA - J a p a n C o m p u t e r
Conf., AFIPS, Oct. T 9 7 ~ - - p p . - ~ i 1 2 1 2 [ ~
• . W. O1]e, "Data D e f i n i t i o n S p e c t r u m
and
Procedurality
Spectrum
in
Data
Base
M a n a g e m e n t S y s t e m s " , J. W. K l i m b i e and
K.
L.
Roffeman
(Eds.) , Data Base M a n a g e m e n t
(Proc. IFTP TC-2
W o r k ' S - - L~n6]~.--on
Data
Base
Management,
Apr.
1974),
N o r t h - H o l l a n d , A m s t e r d a m , Neth., 1974, pp.
28g-293.
"A dual
Data
Base
Management
System
(DBMS)
d e s i g n is p r o p o s e d w i t h i n w h i c h
b o t h n e t w o r k and relational
subsystems
coexist.
The n e t w o r k s u b s y s t e m serves
as the 'operational'
DBMS
with
which
programmers
interface,
while
it also
provides
the
base
upon
which
the
relational
end
user
(query
only)
subsystem
operates".
"The
basic
network
subsystem
...
is
a
limited
subset
of
the
1976
CODASYL
specifications;
and
the
proposed
r e l a t i o n a l q u e r y i n t e r f a c e is a limited
s u b s e t of ... SEQUEL".
"This paper d e s c r i b e s two
spectrums
the
phys-log
s p e c t r u m along w h i c h all
d a t a d e f i n i t i o n l a n g u a g e s m u s t lie
and
the
p r o c e d u r a l i t y s p e c t r u m along w h i c h
a]] l a n g u a g e s to act on a c o m p u t e r i z e d
data
base
m u s t lie.
A proposal for a
multi-stage
data
definition
process
supported
by d i f f e r e n t user i n t e r f a c e s
is
outlined".
[See
also
(Olle,
Ig~4cI].
R.
Rustin
{Ed.1 ,
[STGFIDET]
Workshop
Access, and Control,
Data-Structure-Set
M a y 1974.
T. W. O]le, "Data
Structuring
Facilities
in
C o m m e r c i a l l y A v a i l a b l e DBMS", C o m p u t e r
B u l l e t i n , B r i t i s h C o m p u t e r Soc., s e r i e s 2,
no. I, Sept. 1g~4, pP. 2~-22 and 3~.
Proc.
ACM
S[GMOD
on Data ~ 6 " s c r i p t ~ ,
voW.- 2 f"Data Models:
versus
Relational") ,
"This, the second volume, c o n t a i n s
the
p a p e r s and the t r a n s c r i p t of the d e b a t e
on the d i f f e r e n c e s and s i m i l a r i t i e s
of
the D a t a - S t r u c t u r e - S e t Model v e r s u s the
R e l a t i o n a l Model of data b e t w e e n C.
W.
Bachman
and
E.
F.
Codd".
[This
includes six p a p e r s
((Bachman,
1974),
(Codd
and Date, 1978), (Date and Codd,
]974), (Lucking, 1974), (Sibley, 1974),
and
(Tsichritzis,
1974))
plus
discussion].
"This paper i n t r o d u c e s the n e w
concept
of
a
complete
spectrum
of
data
d e f i n i t i o n f a c i l i t i e s from
the
purely
logical to the c o m p l e t e l y p h y s i c a l .
An
indication
is g i v e n
of
where
major
c o m m e r c i a l l y a v a i l a b l e DBMS lie in this
spectrum.
The
interaction
with
this
spectrum
of
processing
languages
on
v a r i o u s procedural ]evels is d i s c u s s e d .
Finally,
a
potentia]
future role For
the
relational
database
and
its
associated
processing
language
is
suggested"
[gee also (Olle, 19~4b)].
H.A.
Schmid
and
P.
A.
Bernstein,
"A
Multi-level
Architecture
for
Relational
Data
Base
Systems",
Proc.
[1st]
Int].
Conf. on V e r y Large Data Bases, ACM, Sept.
]975, pp. 2 0 2 - 2 2 ~ .
T. W.
O]]e,
"A
Practitioner's
view
of
Relational
Data
Base
Theory",
FDT, ACM
SIGMOD, vo]. 7, no. 3-4, ]g75, p P ~ " ~ - ~ .
"We d e s c r i b e a m u l t i - l e v e l a r c h i t e c t u r e
for
relational
data
base
systems".
[One
level
supports
the
language
described
in (Tsichritzis, 1976).
See
also (Mlug and T s i c h r i t z i s ,
1977)
and
(Tsichritzis, 1975)].
"The ...
paper
represents
a
lightly
edited v e r s i o n of" [fOlle, 19781].
7. g. R o t h n i e and W. T.
Hardgrave,
"Data
Mode]
Theory:
A B e g i n n i n g " , Proc. Fifth
T e x a s Conf. on C o m p u t i n g
£yst.-[----lq~E~'L2C~7
T~.-- T~,
--~. 47 ( a b s t r a c T ; Tech. Rep.
1@, Dept. of Info. Syst. M a n a g e m e n t , U. of
M a r y l a n d , C o l l e g e Park, MD, Sept. ]976.
L.
S.
Schneider,
"A
Relational
Query
Compiler
for
Distributed
Heterogeneous
Databases",
Sterling
Systems
Corp.,
Golden,
CO;
p r e s e n t e d at SHARE 50 Conf.,
Mar. 1978.
"We p r o p o s e that 'data model'
be
used
to
denote:
a c o l l e c t i o n of a b s t r a c t
entities,
facilities
for
defining
a b s t r a c t e n t i t i e s " , [and] "a c o ] l e c t i o n
of o p e r a t i o n s that m a n i p u l a t e
abstract
entities".
"This
paper r e p r e s e n t s an
e m b r i o n i c a t t e m p t to e s t a b l i s h a t h e o r y
"Information
systems
in
which
the
database
is d i s t r i b u t e d
among
many
heterogeneous
representations
are
b e c o m i n g m o r e c o m m o n with the a d v e n t of
computing
networks".
"This
paper
contends
that
a
mapping
from
a
-
65
-
consistent comprehensive
user-view
to
the
semantics
o~
each
target system
involved would reduce this
problem
to
one o{ syntax £or w h i c h known s o l u t i o n s
m a y be
applicable,
and
that
such
a
mapping
can
be
founded
on
the
relational
model
the
Data
~ndependent
Accessing
Model
..., and
the j u x t a p o s i t i o n o{ these".
[See also
(Schneider, Iq75%].
E. H. Sibley, "On the E q u i v a l e n c e s of Data
Based
Systems",
in
(Rustin,
1974), pp.
L. S. ~ c h n e i d e r , "A R e l a t i o n a l V i e w of the
Data
Independent
A c c e s s i n g Model", Proc.
A C M - g I G M O D Intl. Conf.
on
Management
o~
T~-~a, June ~ ,
pD~. 5-~.
E.H.
Sibley
and
L.
Kerschberg,
"Data
Architecture
and
Data
Model
Considerations",
Proc.
Natl.
Computer
Conf.,
AFIPS,
vo~'--216,
June
1977, p p .
85-96.
43-76.
"The two
major
approaches
that
have
e m e r g e d m a y be termed the r e l a t i o n a l or
set t h e o r e t i c , and the data
structured
or
procedural.
There
are
obviously
d i f f e r e n c e s in
these,
but
there
are
also s i m i l a r i t i e s " .
"This paper a t t e m p t s to show
that
the
DIAM's
relevance
to
contemporary
r e s e a r c h in d a t a b a s e
systems
can
be
enhanced
by
viewing
it t h r o u g h n - a r y
relations.
To
accomplish
this,
the
paper
first d e v e l o p s a r e d e f i n i t i o n of
the DIAM String Level in terms of n - a r y
relations.
It
then
appeals
to
the
remaining
levels
of
the
DIAM
to
describe
various
relational
implementation
alternatives".
~See
also (Schneider, Iq78%].
"In the past, a t t e m p t s h a v e
been
made
to
compare
and
c o n t r a s t ... systems,
but the g r e a t e s t d i f f i c u l t y
arises
in
seeking
a common
basis.
This p a p e r
a t t e m p t s to show h o w a g e n e r a l i z e d d a t a
system
(GDS),
represented
by
two
different models,
could
form
such
a
basis;
it
then
proposes
that
data
p o l i c y d e f i n i t i o n s can r e s t r i c t the G D S
to
a
specialized
model,
such
as
a
r e l a t i o n a l or D B T G - l i k e m o d e l " .
D. W. Shipman, "The F u n c t i o n a l Data
Model
and
the
Data
Language
DAPLEX",
Proc.
A C M - S I G M O D IQTg Intl. Conf. on
Management
Data,
M a y ]~-9-d~ p. 59 ( ~ s t r a c t ~ ; to
appear ~n ACM Trans. on D a t a b a s e Syst..
M.
R.
Stonebraker
and
G.
D.
Held,
"Networks,
Hierarchies,
and R e l a t i o n s in
Data Base M a n a g e m e n t S y s t e m s " ,
Proc.
ACM
P a c i f i c 75 R e g i o n a l Conf. (Data:
Its Use,
O r g a n [ Z a ~ ' o n , and M a n a g e m e n t ) ,
Boole
and
Babbage,
Inc.,
S u n n y v a l e , CA, Apr. 1975,
pp. l-g.
"This paper p r e s e n t s and m o t i v a t e s
the
D A P L E X l a n g u a g e and the u n a e r l y i n g data
mode]"
[One s e c t i o n s t a t e s that] "the
data
modelling
c a p a b i l i t i e s of D A P L E X
i n c o r p o r a t e those of the
hierarchical,
relational and n e t w o r k m o d e l s " .
"The
three
models
of
data
that
currently
prevail
are d e s c r i b e d .
One
is the r e l a t i o n a l view".
"The
second
is
the
network
view
advanced
by
CODASYL".
"A
third
view
is
a
hierarchical
one".
"Non-procedural
l a n g u a g e s for all three v i e w s
of
data
are v e r y s i m i l a r " .
"The e x p r e s s i v e n e s s
of the d a t a s t r u c t u r e s is the same for"
[ r e l a t i o n a l and n e t w o r k ] .
B. ~ h n e i d e r m a n and
G.
N.
Thomas,
"Path
Expressions
for
Complex
Queries
and
Database
Program
Conversion",
Automatic
Proc.
6th
Int]. Conf. on V e r y Large D a t a
~-ases, ACM, r~ct. l ~ ' , pp. ~q-z14.
M.
R.
Stonebraker
and
L.
A.
Rowe,
"Observations
on
Data
Manipulation
L a n g u a g e s and their E m b e d d i n g
in G e n e r a l
Purpose
P r o g r a m m i n g L a n g u a g e s " , Proc. 3rd
Intl. Conf. on V e r y Large D a t a Bases, ACM,
Oct. 19w7, Pp. 128-143.
"our e f f o r t s to
develop
an
automatic
database
system
conversion
facility
yielded a powerfu],
yet
simple
query
l a n g u a g e w h i c h was d e s i g n e d for ease of
conversion".
"This
approach
provides
for
a
high
level,
relational-like
f a c i l i t y with the visual and s t r u c t u r a l
appeal
of the n e t w o r k mode]"
"Within
a set instance the r e c o r d s are
in
...
order by the set keys" [as in a C O D A S Y L
set] "and d u p l i c a t e set
keys
are
not
allowed"
[as
in
a
relation,
whose
t u p l e s are unique,
or
a
CODASYL
set
with d u p l i c a t e s not a l l o w e d ] .
" M a n y data base q u e r y
languages,
both
stand-alone
and
coupled
to a g e n e r a l
purpose programming language, have been
proposed"
"Issues
include
the
s p e c i f i c a t i o n of
performance
options,
side
effects,
implicitness,
the
handling
of
types
and
the
time
of
binding".
"The
emphasis
is
on
a
comparative analysis".
-
66
-
K. Tabata, H. M a t s u m o t o , and Y.
Ohno,
"A
DBMS for
a C o m p o s i t e Type of D i s t r i b u t e d
Data Base", Proc. 3rd UqA - J a p a n C o m p u t e r
Conf., ~FTPS, Nct. IQ~e, pp. Ig~-191.
D. C. ~ s i c h r i t z i s ,
"A
Network
Framework
for
Relation
Implementation",
B.
C.M.
D o u q u ~ and G. M. N i j s s e n (Eds.), Data Base
Description
(Proc.
IFIP
TC-2
Spec~l
W o r k i n g Conf. on
Data
Base
Description,
Jan.
lq75),
~orth-Holland,
Amsterdam,
Neth., ]975, pp. 269-282.
"We p r o p o s e a p h i l o s o p h y of a Data Base
Management
System
(DBMS~
for
a
composite
type
of
distributed
data
base.
Component
data
b a s e s being to
c o n s t r u c t the d i s t r i b u t e d data base ...
m a y h a v e data m o d e l s d i f f e r e n t from one
another.
We i n t e g r a t e v a r i o u s kinds of
data
models
into the relational model
to
construct
the
distributed
data
base".
"A n e t w o r k mode] is d e f i n e d in terms of
simple
relationships
among data".
"A
n e t w o r k l a n g u a g e is p r o p o s e d to d e c l a r e
and
manipulate
access
paths
between
data.
It is c l a i m e d that the
proposed
f r a m e w o r k can be a p p r o p r i a t e as a b a s i s
for
relation
implementation".
[See
also
(~lug
and
Tsichritzis,
1977),
(Schmid
and
Bernstein,
1975),
and
(Tsichritzis, 1976)].
N.
Tha]mann
and
D.
Thalmann,
"A
Problem-Oriented
Ana]ys~s
of
Database
Models",
J.
Chemical
Information
and
C o m p u t e r S~Tences, A m e r i c a n Chemical S o c k ,
W a s h i n g t o n , PC, vo]. ]9, no. ~, M a y
]979,
PP. ~5-8q.
Database
J.
D.
Ullman,
Principles
of
Systems,
Computer
ScienCe
Press,
Rockville,
MD,
198~,
Sect.
3.4
( " C o m p a r i s o n of the M o d e l s " ) , pp. 98-100.
"Which is the m o s t c o n v e n i e n t
database
model
considering
specific
applications?
The goal of
this
paper
is
to
try
to answer this q u e s t i o n by
the
use
of
a
chemical
example.
Examples
of
requests
describe
the
p r o b l e m s of
insertion,
deletion,
and
updating;
these r e q u e s t s are a n a l y z e d
for
the
hierarchical
model
and
are
expressed
in
a
relational
language
d e f i n e d by the a u t h o r s and
in
Socrate
for the n e t w o r k model"
D. C. T s i c h r i t z i s , " C o m m e n t s
o6
the
Relational
view",
1974~, pp. 77-81.
"By the c r i t e r i o n of e a s y use, there is
no
doubt
that the r e l a t i o n a l model is
superior".
"When
we
consider
the
p o t e n t i a l for e f f i c i e n t i m p l e m e n t a t i o n ,
the
network
and
hierarchical
models
score high marks".
Y. V a s s i l i o u and F.
H.
Lochovsky,
"DBMS
Transaction
Translation",
Proc.
COMPSAC
90, IEEE-CS,
Oct.
19R~,
pp.
~9-9~;
an
~tended
v e r s i o n , by Y. V a s s i l i o u , a p p e a r s
in F. H. L o c h o v s k y (Ed.) , "A
Panache
of
DBMS
Ideas
If",
C o m p u t e r Syst. R e s e a r c h
Group
Tech.
Rep.
10],
U.
of
Toronto,
Toronto,
Ont.,
Canada,
May
1979,
pp.
92-122.
on A d v a n t a g e s
~n
(Rustin,
"The
principal
advantages
of
the
relational
model
are:
s i m p l i c i t y , in
terms of the
data
and
the
language;
uniformity,
e v e r y t h i n g is based on one
concept;
completeness,
it
is
as
complete
as
anything
else;
data
i n d e p e n d e n c e , both in s t o r a g e s t r u c t u r e
and
growth
independence
for
certain
kinds
of
changes
in
the
schema;
s e c u r i t y and integrity".
"Data
translation
and
transaction
t r a n s l a t i o n are two m a j o r p r o b l e m s that
have to be solved in order
to
achieve
the
coexistence
of
heterogeneous
distributed databases".
"Methods
for
mapping
a
hierarchical
or
network
schema
to
an
equivalent
relational
schema
are
presented"
"Relational
operators
_.
are
translated
to
equivalent
"hierarchical
and
network
operations".
D.
C.
Tsichritzis,
"LSL:
A
Link
and
~ e l e c t o r L a n g u a g e " , Proc. A C M - S I G M O D Intl.
Conf. on M a n a g e m e n t of
Data,
June
1976,
R.
E.
Westgaard,
"A
COBOL
Data
Base
Facility
for
the R e l a t i o n a l Data Model",
Proc. ACM P a c i f i c 75 Regional Conf. (Data:
~---U~,
~--d~a~za~]on,
a~
~[anagement) ,
B o o l e and Babbage,
Inc.,
Sunnyvale,
CA,
Apr. 1975, pp. Iq2-139.
pp. I ~ - 1 3 3 .
"This paper
presents
the
main
ideas
behind
the
l a n g u a g e LgL".
"It can be
thought
of
as
a
relational
system
implemented
on a n e t w o r k e n v i r o n m e n t " .
[gee also (Klug and T s i c h r i t z i s , 1977),
(Schmid
and
Bernstein,
1975),
and
(Tsichritzis, ]g~5)].
"The relationa] data model ... has b e e n
c o n t r a s t e d with the C O D A S Y L DDL n e t w o r k
model as to
effectiveness
in m e e t i n g
the
goals
of
data
independence,
f l e x ~ b i ] i t y in data m o d e l i n g , and
ease
of
use".
"The
CODASYL
DDL
and DML
interfaces
are
oriented
to
the
application
programmer
whereas
the
-
67
-
"An
algorithm
is
presented
for
d e s i g n i n g relational views over network
schemas".
"The p a r t i c u l a r d e c l a r a t i o n s
of
a
CODASYL
schema
which
supply
sources of logical data d e f i n i t i o n
are
first identified.
Then the v i e w d e s i g n
a l g o r i t h m is derived on the basis of
a
formal
analysis
of
the
semantic
constraints
established
by
these
declarations.
A new
form
of
data
s t r u c t u r e d i a g r a m is also introduced to
visualize
these
constraints".
[See
also (Goldman, 1979), (Zaniolo, 1979b) ,
and (Zaniolo, 1977)].
re3at~ona] model
is oriented
to
the
less
procedural
non-programmer.
This
paper
proposes
an
application
programmer
COBOL
interface
for
the
relational
model
utilizing
existing
COBOL
!/O
verbs
and
the C O D A S Y L DDL
c o n s t r u c t s of schema and subscbema".
v.
K.
M.
Whitney,
"Relational
Data
Management
Tmplementation
Techniques",
Proc. ACM S!~MOD
[~IGFIDET]
Workshop
on
Descrlp~,
Access, and Control, Ma-~
"~'~F, pp. 3 2 1 ' - ~ 4 ~ . - [In part of this paper], "the
concepts
o~ m o d e l i n g informat{on s t r u c t u r e s with
data ~s illustrated
w~th
the
CODA~YL
Dm~G and the relational models".
C.
A.
Zaniolo,
"Multimodel
External
Schemas
for
C O D A ~ Y L Data Base M a n a g e m e n t
Systems", G. Bracchi
and
G.
M.
Nijssen
(Eds.) , D a t a Base A r c h i t e c t u r e
(Proc. IFIP
TC-2
Wor~ng
Conf.
On
Data
Base
Architecture,
June
1979), N o r t h - H o l l a n d ,
Amsterdam, Neth., 1979, pp. 171-190.
E. Wong and R. H.
Katz,
"Logical
Design
and
Schema
C o n v e r s i o n for Relational and
DRTG
Databases",
P.
P.-S.
Chen
(Ed.) ,
Proc.
Intl.
Con6. on E n t i t y - R e l a t i o n s h i p
~ a c ~
to Systems A n a l y s ~ s
and
Design,
Dec.
l~TD-~ pp. 9~g'L-~;-----~ate{ p u b ~ d
as E n t i t y - R e ] a t i 0 n s h ~ p A p p r o a c h to ~ y s t e m s
Analysis
and
Design,
NortH-Holland,
Amsterdam, N e ~ . ,
"The
problem
of
designing
and
supporting
relational and h i e r a r c h i c a l
views over C O D A S Y L n e t w o r k
schemas
is
considered".
"A
s o l u t i o n is p r o p o s e d
based on the i n t e g r i t y
constraints
on
logical
data
resulting
from
certain
declarations
in
the
CODASYL
Data
Definition
Language".
[See
also
(Goldman, 197g), (Zaniolo, 1979a) , and
(Zaniolo, 1977)].
"A v a r i a n t oF
the
Entity-Relationship
mode] is proposed as the d a t a model for
logical design".
"Mapping
rules
will
be
proposed
for t r a n s f o r m i n g a d e s i g n
schema ~nto a c o r r e s p o n d i n g
schema
of
either
relational
or DB~G type".
"It
is shown
that
with
relatively
minor
semantic
augmentation
of
DBTG
and
relational ~ a t a models, the m a p p i n g
~s
reversible.
As
a
consequence,
reversible
schema
conversion
between
DBTG
and
re]ationa~
models
becomes
possib3e".
C. A. Zaniolo, "Relational V i e w s in a Data
Base
System:
S u p p o r t for Queries", Proc.
COMPSAC
77,
IEEE-CS,
Nov.
1977,
pp.
267-~5.
"The relational mode]
is
extended
to
include
null
v a l u e s and o p e r a t i o n s on
relations
containing
null
values.
These
c o n c e p t s a l l o w the d e f i n i t i o n of
i n f o r m a t i o n p r e s e r v i n g relational views
over
a n e t w o r k schema.
A m e c h a n i s m is
p r e s e n t e d to support q u e r i e s
on
these
views
without
duplication
of
actual
data".
[See
also
(Goldman,
]979),
(Zanio]o,
1979a),
and
(Zaniolo,
1979b) 3.
C.
Wood,
R.
C.
gummers,
and
E.
B.
wernandez,
"Authorization
in
Multilevel
Database
Models",
Information
Syst.,
P e r g a m o n Press, nxford, UK, vol. 4, no. ~,
1979, pD. 155-I~1.
"In a mult{leve] d a t a b a s e a r c h i t e c t u r e ,
authorization
rules
m a y be w r i t t e n at
the conceptual level or at the external
level.
We analyze here the c o n s i s t e n c y
o~ a u t h o r { z a t i o n rules w r i t t e n at these
two
levels.
We
assume
that
the
conceptual
]eve]
model
is
of
the
entity-relationship
type
and
the
external model is relational"
K. Zimmermann, " D i f f e r e n t Views of a
Data
Base:
Coexistence
B e t w e e n N e t w o r k Model
and Relational Model,', Proc.
list]
Intl.
Conf. on V e r y Large Data Bases, ACM, S e p t l
-[-c~, pp.-~T~-~.
"The p r o b l e m of data
base
access
via
different
data
models
has
been
investigated for the n e t w o r k model
and
the
relational
model.
The
network
model is based on ... Codasyl . . . .
For
a g i v e n n e t w o r k model of the d a t a base
a coexistent
relational
model
is
proposed.
The proposal ~s based on an
e x t e n s i o n of the usual relational model
...
by an i n c o r p o r a t i o n of a p p r o p r i a t e
network p a r a m e t e r s " .
C. A. Zanio]o, "Design o~ Relational V i e w s
Over
Network
Schemas",
Proc. A C M - g I G M O D
l q~g Intl. Conf. on
Manage~en-~ ~
~
~.--1"7~-I ~ - - - ~ - ' ~ - ~ h t ~ - ~ ]~nger
v e r s i o n is
"Design
o ~ ~e]ationml
Views
~ver
a Network
Schema", ~perry R e s e a r c h
Center ReD.
~CRC-RR-nR-37,
Sudbury,
MA,
J u l y ]97~ .
-68~