The LOGRES prototype

The LOGRES F. Cacace,

S. Ceri,

P. Fraternali,

prototype S.

*

Crespi-Reghizzi,

S. Paraboschi,

L. Tanca

Dipartimento

di Elettronica e Informazione Politecnico di Milano Piazza L. Da Vinci, 3220133 Milano, Italy

{ceri,crespi,fraterna,

Logres

is a new-generation

database

parabosc,tanca}

system

now been translated

in-

can be stored tions.

tegrating features from deductive and object-oriented databases [1, 2, 3, 4, 5]. The data model of Logres supports structural and semantic complexity collection of concepts from object-oriented

through a rich models. The

rule language

of complex

ob-

and the definition

of

allows for the manipulation

jects, the generation

of new objects,

passive and active constraints. rules to database ifiers,

which

are the unique a fully

the side effects

procedural

declarative

feature

Normal

gres language lection, built-in

is built

Form

includes

and Intentional

When the application is executed, the Logres application manager produces updates (when needed) to the Data Dictionary and to the Intensional

by means of qualqualifiers

responsible

otherwise

Databases

of Logres,

of set of

on top of Algres

Relational

classical

Database;

relational

operator.

Algres

Logres Database

([6]),

operators

(se-

The Data Model

functions, operators,

stores the Extensional and provides

dictionary,

the run-

to the Extensional query results.

application

is the input

of the Logres

Rule

tional

Compiler,

produces

an Alice

analyzes

the cor-

the Logres

which

integrity

con-

structures

into

receives

the syntactic

and compiles/optimizes

rules, pro-

module.

The Logres system

The application

which

schema-derived

Compiler,

database,

ducing

has a user-friendly

graphical

terface, GRILLO, that allows syntax-directed the Logres applications, and a graph-based

2. The A/ice Compiler receives the module and translates it into C executable code (containing calls to support).

by:

tree and the integrity constraint rules generated by the data model compiler, loads part of the inten-

In C Embedded).

run-time

is composed

straints, and translates Algres data structures.

which is needed in order to execute the application, and finally produces a module, written in Al-

the Algres

changes

rectness of the data structures introduced in the application with respect to the persistent data

Compiler, which analyzes its correctness, detects and loads the part of the Intensional Database

ice (ALgres

doing

The Logres compiler

The Logres

for

and for producing

the Al-

time environment of Logres applications; when an application is issued, the programming chain is the following: 1. The

and

applica-

of rules;

join, projection, etc.) plus aggregate predicates, nesting and unnesting

and a fixpoint

format,

of executable

language.

The Logres prototype a Non-First

into an executable

in a library

Database and sends the executable code of the application to the Alice Run-Time Support, which is

The application

states is controlled

dictate

@ipmel2.elet.polimi.it

tion of the Logres Database

has

schema; from

in-

editing of visualiza-

the interface,

it is possible to invoke the compilation and running of Logres applications, with windows displaying diagnostic messages and query results.

*This work was partially supported by the project LOG IDATA+, of the National Research Council of Italy, and by the Esprit project STRETCH, sponsored by the EEC. Permission to copy without fee all or part of this material is granted provided that the copias ara not made or distributed for direct commercial advantage, tha ACM copyright notica and the title of the publication and its date appear, and notice is given that copying is by permission of the Association for Computing Machinery. To copy otherwise, or to republish, requires e fee and/or specifi”c permission. SIGMOD /5/931VVashington, DC, USA e 1993 ACM 0-89791 -592-519310005 /0550 ...91 .50

References [1] Cacace, F.: Data Model Choices litecnico

550

“Implementing

an Object-Oriented

in

Relational

Extended

and Complexity”, Report di Milano, January 1990.

Algebra:

n. 90-009,

Po-

F., S. Ceri, S. Crespi-Reghizzi, L. Tanca, R. Zicari: “IntegratingO bject-OrientedD ataModcling with a Rule-Based Programming Paradigm”, Conf. on the Managein Proc. ACM-SIGMODInt. ment of Data, SIG MOD 1990, Atlantic City, May 1990.

[6] Ceri,

[2] Cacace,

[3] Cacace,

F., S. Ceri,

“Designing

S. Crespi-Reghizzi,

and Prototyping

gineering,

[5] Cacace,

di Milano, F., S. Ceri

of queries. “Consistency

Language”, in Proc. MFDBS Conference, LNCS 495, Springer-Verlag, May 1991.

upper

Restock,

I quesp-be SyStuns-slalnes

spmptsml

hld

mm-$

concerning

tutoring

of helicopter

time of malfunctions

in the helicopter

These are expressed

window

on the right

[3].

engine.

ing the

relations

bottom

window

by means of rules; the

query-time on the right

and

query-tool.

shows part

Rules

—m

~ULES SECTION W ~$@=$ M$@SN)SW@=~,@$= TM)Cstpaks Ihqpmcedm Sl&P,psubEsllse talksn pmcdxs@P,q@cmkcASSTM,cbns rqdn&T usmnblsd sPstsms(ASSTM,sIrwtsyusssmSTM smct @asis(STM,sP$IWMSTMS} @aIu(STMSx@U$U smwSN). quay ted(m

amIMSN,~SYM,tsskTLL)crepslrs IJat@ocuhre oIitP,~b smue tdMYTI procedms(P,sp@c@mASSTM,fxals -T manbsr(T~TLSFT’),TLL-TL ssmsnbledsystuas(ASSTM,saUctsTSMMSTM. spstsms(STM,systraxSTMS), swu $TKMM(STMS,$P-U-MI= SN).

I I

tooks

qmptwsEs -S

~tud

R$4*1

w.lmlo2sssTo*s@mmd

The

of the query

~

$m=f-n-s

a knowlpilots

shows the Logres rules defin-

answers.

quay-ml

m--$

in

Windows can be opened on Logres schema-s, rules, and databases. The leftmost window shows the structure of three intensional relations representing the result

and Po-

Programming

applications”,

1990.

demo shows an example

and repair

in a Database

complex

L.

Advanced

The figure shows part of an application which queries the database for details about symptoms, fixing tools,

EnEn-

and L. Tanca:

for

7:4, July

Lamperti, An

Demo

The

1992.

and non-determinism

system

G.

“ALGRES:

Zicari:

edge base for automated

18:6, June 1992.

[4] Cacace, F., S. Ceri, and L. Tanca: “Design Implementation of Logres” Report n. 92-040, litecnico

database

Logres

Appli-

cations in the Logres and Algres programming vironment’), in IEEE Transactions on Soflware

S. Crespi-Reghizzi, R.

IEEE-So flware

L. Tanca:

Data-Intensive

S.,

Lavazza,

I