UNIVERSIT?AT

HANNOVER

Institut

f?ur

Informatik

Fachgebiet

Datenbanken

und

Informationssysteme

Prof.

Dr.

Udo

W.

Lipeck

Lange

Laube

D

-LCB-

Hannover

Phone

+49 511 762-4950

Fax

+49 511 762-4961

E-mail

ul@informatik.uni-hannover.de

Papers

of

the

Database

and

Information

Systems

Group

This

is

a

list

of

selected

papers

-LRB-

co

-RRB-

authored

by

members

of

the

Database

and

Information

Systems

Group

at

the

University

of

Hannover

To

obtain

copies

free

of

charge

-LRB-

hard

copies

while

supply

lasts

-RRB-

please

write

or

e-mail

to

Frau

Regina

Schumann

Institut

f?ur

Informatik

Universit?at

Hannover

Lange

Laube

Hannover

-LRB-

rs@informatik.uni-hannover.de

-RRB-

using

the

order

numbers

given

below

Selected

papers

are

available

also

in

postscript

or

dvi

form

via

anonymous

FTP

on

ftp.informatik.uni-hannover

de

-LSB-

-RSB-

in

the

papers

directory

Last

update

on

Mai

Literatur

-LSB-

-RSB-

S.

Brass

J.

Dix

T.

C.

Przymusinski

Characterizations

and

Implementation

of

Static

Semantics

of

Disjunctive

Programs

Technical

report

Universit?at

Hannover

Institut

f?ur

Informatik

In

recent

years

much

work

was

devoted

to

the

study

of

theoretical

foundations

of

Disjunctive

Logic

Programs

and

Disjunctive

Deductive

Databases

While

the

semantics

of

non-disjunctive

programs

is

fairly

well

understood

and

there

exist

several

implementations

of

the

best

known

semantics

-LRB-

well-founded

semantics

and

stable

semantics

-RRB-

the

declarative

and

computational

foundations

of

disjunctive

programming

proved

to

be

much

more

elusive

and

difficult

Consequently

as

of

now

there

is

no

general

agreement

concerning

the

proper

semantics

of

disjunctive

programs

Quite

recently

however

two

new

and

very

promising

semantics

have

been

proposed

for

the

class

of

disjunctive

logic

programs

Both

of

them

extend

the

well-founded

semantics

of

normal

programs

The

first

one

is

the

static

semantics

proposed

by

Przymusinski

and

the

other

is

the

D-WFS

semantics

proposed

by

Brass

and

Dix

Although

the

two

semantics

are

based

on

very

different

ideas

they

turn

out

to

be

quite

closely

related

and

in

fact

they

are

completely

equivalent

when

restricted

to

the

suitable

common

language

This

paper

is

devoted

to

an

in-depth

study

of

the

static

semantics

in

the

class

of

so

called

super-programs

which

properly

contains

the

class

of

disjunctive

logic

programs

We

first

establish

three

powerful

syntactic

and

semantic

characterizations

of

the

static

semantics

significantly

simplifying

the

original

definition

Subsequently

we

demonstrate

the

applicability

and

importance

of

the

above

characterizations

by

using

one

of

them

as

an

inference

engine

in

a

Prolog

implementation

of

an

query-answering

interpreter

for

static

semantics

in

the

class

of

super-programs

-LSB-

-RSB-

S.

Brass

SLDMagic

An

Improved

Magic

Set

Technique

Technical

report

Institut

f?ur

Informatik

Universit?at

Hannover

We

present

a

rewriting

method

for

Datalog-programs

which

simulates

SLD-resolution

more

closely

than

the

ordinary

magic

set

method

does

This

is

especially

advantageous

in

the

case

of

tail-recursive

programs

but

already

in

non-recursive

programs

we

can

often

save

a

number

of

joins

Furthermore

we

get

some

other

known

optimizations

for

free

when

we

simulate

SLD-resolution

in

this

way

Based

on

an

idea

of

Bry

our

method

can

be

described

in

an

elegant

way

by

means

of

a

meta-interpreter

In

contrast

to

the

method

described

in

-LRB-

Brass

-RRB-

we

can

now

handle

the

full

range

from

a

direct

simulation

of

SLD-resolution

to

the

standard

magic

set

technique

The

integration

of

the

two

methods

also

removes

the

restriction

to

tail-recursive

programs

of

-LRB-

Brass

-RRB-

In

contrast

to

the

method

of

Ross

we

do

not

only

solve

the

problem

of

tail-recursion

but

try

to

simulate

SLD-resolution

as

fully

as

possible

-LSB-

-RSB-

M.

Gertz

G.

Koschorreck

U.

W.

Lipeck

M.

Bethke

R.

Gr?utzner

A.

Schl?uter

ODDIS

-LCB-

Ein

Informationssystem

f?ur

das

Oracle

Data

Dictionary

Universit?at

Hannover

Institut

f?ur

Informatik

Hannover

erscheint

im

Datenbank-Rundbrief

-LSB-

-RSB-

M.

Gertz

U.

W.

Lipeck

Deriving

Optimized

Integrity

Monitoring

Triggers

from

Dy

namic

Integrity

Constraints

Institut

f?ur

Informatik

Universit?at

Hannover

Hannover

To

appear

in

Data

Knowledge

Engineering

Modern

approaches

to

integrity

monitoring

in

active

databases

suggest

to

generate

triggers

from

constraints

as

part

of

database

design

and

to

utilize

constraint

simplification

techniques

for

trigger

optimization

Such

proposals

however

have

been

restricted

to

static

conditions

only

In

this

paper

we

show

how

to

derive

triggers

from

dynamic

integrity

constraints

which

describe

properties

of

state

sequences

and

which

can

be

specified

by

formulas

in

temporal

logic

Such

constraints

can

equivalently

be

transformed

into

transition

graphs

which

describe

such

life

cycles

of

database

objects

that

are

admissible

with

respect

to

the

constraints

Nodes

correspond

to

situations

in

life

cycles

and

edges

give

the

-LRB-

changing

-RRB-

conditions

under

which

a

change

into

another

situation

is

allowed

If

object

situations

are

stored

integrity

monitoring

triggers

can

be

generated

from

transition

graphs

for

all

situations

and

all

critical

database

operations

Additionally

new

simplification

techniques

can

be

developed

by

identifying

characteristic

preconditions

in

the

graphs

and

by

utilizing

invariants

Maintenance

of

object

situations

can

be

supported

by

triggers

as

well

Keywords

Active

databases

Constraint

simplification

Dynamic

integrity

constraints

Integrity

enforcement

Object

life

cycles

Temporal

formulas

Triggers

-LSB-

-RSB-

S.

Brass

J.

Dix

A

General

Approach

to

Bottom-Up

Computation

of

Disjunctive

Semantics

In

J.

Dix

L.

M.

Pereira

T.

Przymusinski

-LRB-

eds

-RRB-

Nonmonotonic

Extensions

of

Logic

Programming

LNAI

Springer-Verlag

-LCB-

Our

goal

is

to

derive

bottom-up

query-evaluation

algorithms

from

abstract

properties

of

the

underlying

negation

semantics

In

this

paper

we

demonstrate

our

approach

for

the

disjunctive

stable

model

semantics

but

the

ideas

are

applicable

to

many

other

semantics

as

well

Our

framework

also

helps

to

understand

and

compare

other

proposed

query

evaluation

algorithms

It

is

based

on

the

notion

of

conditional

facts

developed

by

Bry

and

Dung/Kanchanasut

We

start

by

computing

a

residual

program

and

show

that

it

is

equivalent

to

the

original

program

under

very

general

conditions

on

the

semantics

-LRB-

which

are

satisfied

e.g.

by

the

well-founded

stable

stationary

and

static

semantics

-RRB-

Many

queries

can

already

be

answered

on

the

basis

of

the

residual

program

For

the

remaining

literals

we

propose

to

use

an

appropriate

completion

of

the

residual

program

which

syntactically

characterizes

the

intended

models

In

the

case

of

the

stable

model

semantics

we

utilize

an

interesting

connection

to

Clark

's

completion

-LSB-

-RSB-

S.

Brass

J.

Dix

Disjunctive

Semantics

based

upon

Partial

and

Bottom-Up

Evaluation

In

L.

Sterling

-LRB-

ed

-RRB-

Twelfth

International

Conference

on

Logic

Programming

-LRB-

ICLP

-RRB-

The

MIT

Press

-LCB-

-LSB-

-RSB-

S.

Brass

J.

Dix

Characterizations

of

the

Stable

Semantics

by

Partial

Evaluation

In

A.

Nerode

-LRB-

ed

-RRB-

Logic

Programming

and

Nonmonotonic

Reasoning

-LRB-

LP&NMR

-RRB-

LNCS

Springer-Verlag

-LCB-

There

are

three

most

prominent

semantics

defined

for

certain

subclasses

of

disjunctive

logic

programs

GCWA

-LRB-

for

positive

programs

-RRB-

PERFECT

-LRB-

for

stratified

programs

-RRB-

and

STABLE

-LRB-

defined

for

the

whole

class

of

all

disjunctive

programs

-RRB-

Whilst

there

are

various

competitors

based

on

models

notably

WFS

and

its

disjunctive

counterparts

there

are

no

other

semantics

consisting

of

models

We

argue

that

the

reason

for

this

is

the

Partial

Evaluation-property

-LRB-

also

called

Unfolding

or

Partial

Deduction

-RRB-

wellknown

from

Logic

Programming

In

fact

we

prove

characterizations

of

these

semantics

and

show

that

if

a

semantics

SEM

satisfies

Partial

Evaluation

and

Elimination

of

Tautologies

then

-LRB-

-RRB-

SEM

is

based

on

minimal

models

for

positive

programs

and

-LRB-

-RRB-

if

SEM

satisfies

in

addition

Elimination

of

Inconsistencies

it

is

based

on

stable

models

We

also

show

that

if

we

require

Isomorphy

and

Relevance

then

STABLE

is

completely

determined

on

the

class

of

all

stratified

disjunctive

logic

programs

The

underlying

notion

of

a

semantics

is

very

general

and

our

abstract

properties

state

that

certain

syntactical

transformations

on

programs

are

equivalence

preserving

-LSB-

-RSB-

S.

Brass

DP

A

System

for

Reasoning

with

Supernormal

Defaults

In

G.

Brewka

C.

Witteveen

-LRB-

eds

-RRB-

Proceedings

of

the

Dutch/German

Workshop

on

Nonmonotonic

Reasoning

DP

is

a

top-down

theorem

prover

for

supernormal

or

Poole-type

defaults

Axioms

and

defaults

can

be

arbitrary

clauses

i.e.

it

supports

disjunctions

and

-LRB-

real

-RRB-

classical

negation

Multiple

disjunctions

can

be

handled

credulously

skeptically

and

carefully

In

skeptical

mode

the

expressivity

of

supernormal

defaults

corresponds

to

variable

circumscription

The

system

is

based

on

model

elimination

implemented

in

a

way

very

similar

to

Prolog

interpreters

It

is

quite

efficient

in

comparison

with

meta-interpreters

DP

is

freely

avialable

via

ftp

-LRB-

currently

only

in

binary

form

-RRB-

Version

is

still

limited

with

respect

to

the

type

system

and

the

user

interface

but

it

is

at

least

sufficent

for

classroom

demonstrations

We

plan

to

further

develop

DP

to

make

it

a

powerful

tool

for

real

applications

-LSB-

-RSB-

S.

Brass

Magic

Sets

vs.

SLD-Resolution

In

J.

Eder

L.

A.

Kalinichenko

-LRB-

eds

-RRB-

Advances

in

Databases

and

Information

Systems

-LRB-

ADBIS

-RRB-

Springer

-LCB-

It

is

by

now

folklore

that

the

bottom-up

evaluation

of

a

program

after

the

magic

set

transformation

is

as

efficient

as

top-down

evaluation

There

are

a

number

of

formalizations

of

this

in

the

literature

However

the

naive

formalization

is

false

As

shown

by

Ross

SLD-resolution

can

be

much

more

efficient

than

bottom-up

evaluation

with

magic

sets

on

tail-recursive

programs

We

show

that

this

happens

only

for

tail-recursive

programs

and

that

the

only

problem

of

magic

sets

is

the

materialization

of

lemmas

So

magic

sets

are

always

as

goaldirected

as

SLD-resolution

These

results

are

not

surprising

but

we

believe

that

the

variants

given

here

are

especially

useful

for

teaching

purposes

We

also

give

rather

simple

proofs

Furthermore

we

demonstrate

that

SLD-resolution

can

be

directly

simulated

by

bottom-up

evaluable

programs

if

all

recursions

are

tail-recursive

This

is

based

on

the

meta-interpreter

approach

of

Bry

and

seems

to

be

very

promising

-LSB-

-RSB-

M.

Gertz

U.

W.

Lipeck

A

Diagnostic

Approach

to

Repairing

Constraint

Violations

in

Databases

Informatik-Berichte

Institut

f?ur

Informatik

Universit?at

Hannover

Hannover

Repairing

violations

of

integrity

constraints

in

databases

can

be

seen

as

an

interleaving

diagnostic/repair

process

In

this

paper

we

introduce

a

new

approach

on

repairing

constraint

violations

by

adopting

existing

techniques

from

model

-LCB-

based

diagnosis

Violations

of

integrity

constraints

observed

in

an

inconsistent

database

state

are

diagnosed

and

repair

actions

are

deduced

from

diagnoses

By

interleaving

diagnosing

constraint

violations

and

performing

repair

actions

transactions

are

computed

which

restore

the

consistency

of

the

database

-LSB-

-RSB-

M.

Gertz

U.

W.

Lipeck

Temporal

Integrity

Constraints

in

Temporal

Databases

In

J.

Clifford

A.

Tuzhilin

-LRB-

eds

-RRB-

Recent

Advances

in

Temporal

Databases

-LCB-

Proceed

ings

of

the

International

Workshop

on

Temporal

Databases

Sept.

Workshops

in

Computing

Springer-Verlag

Berlin

-LCB-

In

this

paper

we

consider

a

class

of

integrity

constraints

which

describe

admissible

lifecycles

of

database

objects

and

which

can

be

specified

by

transition

graphs

We

present

an

algorithmic

scheme

for

monitoring

such

constraints

in

temporal

databases

which

efficiently

support

the

concept

of

valid-time

The

keys

to

efficient

monitoring

lie

in

storing

lifecycle

situations

with

respect

to

constraints

in

utilizing

the

property

of

graphs

being

iteration-invariant

and

in

using

basic

operations

of

temporal

databases

to

determine

validity

intervals

In

particular

we

give

hints

how

to

extend

monitoring

to

transactions

that

involve

retroactive

and

proactive

modifications

-LSB-

-RSB-

M.

Gertz

U.

W.

Lipeck

A

Diagnostic

Approach

to

Repairing

Constraint

Violations

in

Databases

In

W.

Nejdl

-LRB-

ed

-RRB-

Sixth

International

Workshop

on

Principles

of

Diag

nosis

-LRB-

DX

-RRB-

Working

Papers

October

Goslar

Germany

Universit?at

Hannover

Hannover

-LCB-

Repairing

violations

of

integrity

constraints

in

databases

can

be

seen

as

an

interleaving

diagnostic/repair

process

In

this

paper

we

introduce

a

new

approach

on

repairing

constraint

violations

by

adopting

existing

techniques

from

model

-LCB-

based

diagnosis

Violations

of

integrity

constraints

observed

in

an

inconsistent

database

state

are

diagnosed

and

repair

actions

are

deduced

from

diagnoses

By

interleaving

diagnosing

violations

and

performing

repair

actions

transactions

are

computed

which

restore

the

consistency

of

the

database

-LSB-

-RSB-

V.

Kouramajian

M.

Gertz

A

Visual

Query

Language

for

Temporal

Databases

Informatik-Berichte

Institut

f?ur

Informatik

Universit?at

Hannover

Hannover

This

paper

addresses

the

issue

of

visual

query

formulation

for

temporal

databases

We

introduce

a

number

of

visual

constructs

that

allow

users

to

build

queries

in

a

modular

bottom

-LCB-

up

fashion

based

on

a

temporal

Extended

Entity

-LCB-

Relationship

Model

These

constructs

are

Temporal

projection

temporal

selection

time

links

filtering

and

set

operators

and

temporal

aggregates

This

paper

also

identifies

the

main

challenges

posed

by

visual

interface

design

for

temporal

databases

It

presents

guidelines

for

designing

user

-LCB-

friendly

flexible

visual

environment

for

temporal

design

editors

temporal

query

editors

temporal

update

editors

and

temporal

display

editors

-LSB-

-RSB-

V.

Kouramajian

M.

Gertz

A

Graphical

Query

Language

for

Temporal

Databases

In

M.

P.

Papazoglou

-LRB-

ed

-RRB-

OOER

Object-Oriented

and

Entity-Relationship

Modeling

LNCS

Springer-Verlag

Berlin

-LCB-

This

paper

addresses

the

issue

of

visual

query

formulation

for

temporal

databases

We

introduce

a

number

of

visual

constructs

that

allow

users

to

build

queries

in

a

modular

fashion

based

on

a

temporal

Extended

Entity

-LCB-

Relationship

Model

These

constructs

are

Temporal

projection

temporal

selection

time

links

filtering

and

set

operators

and

temporal

aggregates

-LSB-

-RSB-

S.

Brass

J.

Dix

A

Disjunctive

Semantics

Based

on

Unfolding

and

Bottom-Up

Evalu

ation

In

B.

Wolfinger

-LRB-

ed

-RRB-

Innovationen

bei

Rechen

und

Kommunikationssystemen

GI-Jahrestagung

im

Rahmen

des

World

Computer

Congress

IFIP

Congress

Informatik

aktuell

Springer-Verlag

Berlin

-LCB-

We

define

a

new

semantics

for

disjunctive

logic

programs

in

an

abstract

way

as

the

weakest

semantics

with

certain

properties

the

most

important

being

the

unfolding-property

-LRB-

GPPE

-RRB-

Our

semantics

is

similar

to

the

strong

well-founded

semantics

proposed

by

Ross

but

seems

to

be

more

regularly

behaved

It

is

an

extension

of

both

the

well-founded

semantics

WFS

and

the

generalized

closed

world

semantics

GCWA

We

then

present

a

bottom-up

query-evaluation

method

for

this

semantics

An

important

feature

of

our

approach

is

that

we

directly

derive

the

algorithm

from

the

given

abstract

properties

of

the

logic

programming

semantics

The

idea

of

the

method

is

to

compute

derived

rule

instances

with

purely

negative

bodies

and

then

to

apply

reduction

steps

in

order

to

eliminate

the

conditions

where

possible

-LSB-

-RSB-

S.

Brass

Modular

Specifications

with

Supernormal

Defaults

Annals

of

Mathematics

and

Artificial

Intelligence

-LRB-

-RRB-

-LCB-

We

add

a

simple

module

system

to

specifications

with

supernormal

defaults

It

allows

to

distinguish

between

defining

and

calling

occurrences

of

predicates

This

greatly

improves

the

understandability

of

large

default

specifications

and

especially

helps

to

solve

the

problem

of

unwanted

contrapositions

of

rules

Our

approach

is

similar

to

the

distinction

between

head

and

body

of

logic

programming

rules

but

it

works

on

the

higher

level

of

default

theories

So

our

results

can

help

to

integrate

both

approaches

at

least

on

the

semantical

side

for

specification

purposes

We

also

clarify

the

relation

to

prioritized

defaults

and

argue

that

modular

specifications

are

often

preferable

Finally

we

give

a

theoretical

basis

for

query

evaluation

-LSB-

-RSB-

S.

Brass

Improved

Bottom-Up

Query

Evaluation

in

Positive

Disjunctive

Databases

In

B.

Wolfinger

-LRB-

ed

-RRB-

Innovationen

bei

Rechen

und

Kommunikationssystemen

GI-Jahrestagung

im

Rahmen

des

World

Computer

Congress

IFIP

Congress

Informatik

aktuell

Springer-Verlag

Berlin

-LCB-

It

is

known

that

bottom-up

query

evaluation

can

be

extended

to

work

with

disjunctive

facts

but

there

seems

to

be

the

common

assumption

that

it

is

much

too

inefficient

for

practical

applications

In

this

paper

we

improve

the

extended

bottom-up

evaluation

by

making

the

resolvable

literal

in

a

disjunctive

fact

unique

In

many

cases

this

reduces

an

exponential

behaviour

to

a

polynomial

one

We

apply

this

idea

in

a

Horn-clause

bottomup

metainterpreter

for

positive

disjunctive

rules

and

also

sketch

further

possible

improvements

This

should

make

bottom-up

query

evaluation

for

disjunctive

databases

practically

possible

-LSB-

-RSB-

M.

Dionisio

S.

Brass

M.

Ryan

U.

W.

Lipeck

Hypothetical

Reasoning

with

Defaults

Internal

Report

Institut

f?ur

Informatik

Universit?at

Hannover

Hannover

Sub

mitted

for

publication

A

wide

range

of

properties

of

a

specification

with

Poole-type

defaults

can

be

formally

expressed

by

the

truth

of

modal

formulas

in

its

preference

relation

-LRB-

viewed

as

a

modal

model

-RRB-

We

show

in

this

paper

how

hypothetical

properties

can

be

expressed

in

the

same

manner

These

are

the

properties

that

a

specification

would

have

if

axioms

or

defaults

were

added

Implicit

in

this

result

is

a

way

of

evaluating

truth

of

such

formulas

Any

property

of

a

specification

with

defaults

is

equivalent

to

a

hypothetical

property

of

the

corresponding

specification

without

defaults

Properties

of

specifications

without

defaults

can

however

be

evaluated

by

checking

classical

consequence

and

consistency

with

the

axioms

-LSB-

-RSB-

F.

M.

Dion

sio

U.

W.

Lipeck

S.

Brass

Composition

of

Default

Specifications

To

appear

in

Proc

of

the

International

Workshop

on

Information

Systems

Correctness

and

Reusability

-LRB-

IS-CORE

-RRB-

World

Scientific

Publishers

In

this

paper

we

identify

and

explain

different

types

of

composition

of

specifications

using

defaults

Such

defaults

model

overridable

rules

in

object

specifications

When

composing

object

specifications

it

is

desirable

to

control

to

what

degree

the

intended

behavior

of

the

composition

depends

on

the

local

intended

behaviors

For

this

purpose

two

types

of

composition

open

and

closed

composition

are

studied

Open

composition

allows

for

unrestricted

overwriting

of

the

information

present

in

each

of

the

local

modules

Closed

composition

on

the

other

hand

displays

the

best

possible

agreement

of

the

local

modules

Its

intended

behavior

is

build

from

the

intended

behavior

of

the

modules

to

be

composed

The

two

kinds

of

composition

are

formally

analyzed

within

an

institutional

framework

for

compatibility

of

their

syntactical

and

semantical

levels

which

are

formed

by

appropriate

categories

of

specifications

and

of

preference

relations

on

models

-LSB-

-RSB-

M.

Gertz

D.

Kowalewski

C.

Stolpmann

ICE

Eine

Umgebung

f?ur

den

in

tegrit?atszentrierten

Datenbank-Entwurf

Supplement

I

Benutzerhandbuch

Informatik

Berichte

-LRB-

I

-RRB-

Institut

f?ur

Informatik

Universit?at

Hannover

Hannover

-LSB-

-RSB-

M.

Gertz

D.

Kowalewski

C.

Stolpmann

ICE

Eine

Umgebung

f?ur

den

integrit?atszentrierten

Datenbank-Entwurf

Supplement

II

Programmierhandbuch

Informatik-Berichte

-LRB-

II

-RRB-

Institut

f?ur

Informatik

Universit?at

Hannover

Hannover

-LSB-

-RSB-

M.

Gertz

U.

W.

Lipeck

ICE

An

Environment

for

Integrity-Centered

Database

Design

Informatik-Berichte

Institut

f?ur

Informatik

Universit?at

Hannover

Hannover

The

specification

and

transformation

of

integrity

constraints

into

integrity

maintaining

mechanisms

forms

a

main

task

in

the

database

design

process

Since

these

transformations

require

a

lot

of

administration

for

combining

refining

and

revising

elements

of

a

database

schema

like

static

and

dynamic

integrity

constraints

transactions

and

triggers

a

computer-aided

design

environment

is

strongly

needed

In

this

paper

we

present

an

environment

for

the

integrity-centered

database

design

which

supports

this

process

from

the

first

specification

of

a

database

schema

up

to

the

implementation

of

respective

integrity

maintaining

mechanisms

i.e.

integrity

preserving

transactions

and

integrity

maintaining

triggers

The

presented

system

comprises

tools

for

all

essential

database

design

tasks

needed

for

behavioral

database

modelling

-LSB-

-RSB-

M.

Gertz

U.

W.

Lipeck

ICE

An

Environment

for

Integrity-Centered

Database

Design

In

U.

W.

Lipeck

G.

Vossen

-LRB-

eds

-RRB-

Formale

Grundlagen

f?ur

den

Entwurf

von

Informa

tionssystemen

GI-Workshop

Tutzing

Mai

Informatik-Berichte

Universit?at

Hannover

Hannover

-LCB-

-LSB-

extended

version

appeared

as

-RSB-

-LSB-

-RSB-

M.

Gertz

Specifying

Reactive

Integrity

Control

for

Active

Databases

In

J.

Widom

S.

Chakravarthy

-LRB-

eds

-RRB-

RIDE

Fourth

International

Workshop

on

Research

Issues

in

Data

Engineering

IEEE

Computer

Society

Press

Los

Alamitos

CA

-LCB-

Recent

approaches

to

integrity

enforcement

in

active

databases

suggest

not

only

to

check

constraint

violations

by

triggers

but

also

to

utilize

triggers

to

perform

inconsistency

repair

actions

However

for

sophisticated

reactions

these

approaches

often

require

refinements

of

already

derived

integrity

maintaining

and

inconsistency

repairing

triggers

We

argue

that

analyzing

and

specifying

reactions

on

constraint

violations

should

exclusively

be

carried

out

in

the

conceptual

design

We

provide

a

declarative

specification

language

for

reactions

on

violations

with

an

operational

semantics

suitable

to

express

most

of

the

designers

intended

behavior

on

constraint

violations

We

describe

a

design

methodology

for

reaction

specifications

followed

by

a

procedure

to

derive

a

set

of

stratified

integrity

enforcing

triggers

-LSB-

-RSB-

U.

W.

Lipeck

S.

Brass

Object-Oriented

System

Specification

Using

Defaults

In

K.

von

Luck

H.

Marburger

-LRB-

eds

-RRB-

Management

and

Processing

of

Complex

Data

Structures

Third

Workshop

on

Information

Systems

and

Artificial

Intelligence

Proceedings

Lecture

Notes

in

Computer

Science

Springer-Verlag

Berlin

-LCB-

-LSB-

-RSB-

U.

W.

Lipeck

M.

Gertz

G.

Saake

Transitional

Monitoring

of

Dynamic

Integrity

Constraints

Bulletin

of

the

Technical

Committee

on

Data

Engineering

-LRB-

-RRB-

-LCB-

-LRB-

Special

Issue

on

Database

Constraint

Management

-RRB-

-LSB-

-RSB-

U.

W.

Lipeck

G.

Vossen

-LRB-

eds

-RRB-

Formale

Grundlagen

f?ur

den

Entwurf

von

Informa

tionssystemen

GI-Workshop

Tutzing

Mai

Informatik-Berichte

Universit?at

Hannover

Hannover

-LSB-

-RSB-

H.

Zhou

Uberwachung

dynamischer

Integrit?atsbedingungen

in

vergangenheitsbezo

gener

und

gemischter

temporaler

Logik

Informatik-Berichte

Institut

f?ur

Infor

matik

Universit?at

Hannover

Hannover

-LSB-

-RSB-

H.

Zhou

Anwendung

temporaler

Logiken

zur

Uberwachung

dynamischer

In

tegrit?atsbedingungen

von

Datenbanken

Dissertation

Institut

f?ur

Informatik

Universit?at

Hannover

Hannover

-LSB-

no

copies

available

-RSB-

-LSB-

-RSB-

S.

Brass

U.

W.

Lipeck

Bottom-Up

Query

Evaluation

with

Partially

Ordered

Defaults

In

S.

Ceri

K.

Tanaka

S.

Tsur

-LRB-

eds

-RRB-

Deductive

and

Object-Oriented

Databases

Proceedings

DOOD

Lecture

Notes

in

Computer

Science

Springer-Verlag

Berlin

-LCB-

We

propose

a

query-evaluation

algorithm

for

database

specifications

consisting

of

overridable

rules

-LRB-

defaults

-RRB-

and

non-overridable

rules

-LRB-

axioms

-RRB-

Both

kinds

of

rules

may

contain

disjunctions

Preferences

among

the

defaults

are

given

by

a

partial

order

which

corresponds

to

a

subclass

relationship

allowing

multiple

inheritance

We

use

a

bottom-up

theorem

proving

procedure

It

is

applied

to

the

set

of

-LRB-

disjunctively

-RRB-

assumed

default

instances

which

essentially

can

again

be

computed

by

bottom-up

evaluation

Our

approach

has

two

main

advantages

First

it

gives

a

simple

foundation

for

bottom-up

evaluation

in

the

presence

of

defaults

this

can

be

taken

as

a

basis

for

different

optimizations

Second

in

contrast

to

other

deduction

algorithms

it

is

able

to

handle

partially

ordered

defaults

with

a

skeptical

minimal

model

semantics

-LSB-

-RSB-

S.

Brass

U.

W.

Lipeck

P.

Resende

Specification

of

Object

Behaviour

with

De

faults

In

U.

W.

Lipeck

G.

Koschorreck

-LRB-

eds

-RRB-

Proceedings

of

the

International

Work

shop

on

Information

Systems

-LCB-

Correctness

and

Reusability

-LRB-

IS-CORE

-RRB-

Informatik

Berichte

Universit?at

Hannover

Hannover

-LCB-

In

this

paper

we

present

how

to

extend

object

specification

logic

by

defaults

Thus

overridable

rules

may

be

used

in

specifications

which

deal

not

only

with

object

states

but

also

with

dynamic

object

behaviour

like

enabling

occurrence

of

actions

and

temporal

evolution

Defaults

are

particularly

useful

to

formalize

implicit

negation

the

minimal

change

semantics

of

actions

inheritance

between

object

classes

and

aggregation

of

objects

We

demonstrate

this

by

means

of

examples

and

study

which

default

patterns

should

be

used

for

typical

problems

of

behaviour

specification

-LSB-

-RSB-

S.

Brass

U.

W.

Lipeck

P.

Resende

Instantiation

Semantics

of

Temporal

Defaults

Institut

f?ur

Informatik

Universit?at

Hannover

Hannover

Defaults

are

useful

in

temporal

logic

e.g.

in

order

to

formalize

implicit

negation

the

minimal

change

frame

rule

and

inheritance

with

overriding

Temporal

specification

formalisms

usually

have

such

defaults

built-in

but

the

on-going

discussion

about

the

right

implicit

assumptions

suggests

that

these

assumptions

are

application-dependent

and

should

be

explicitly

specified

by

means

of

defaults

However

the

classical

semantics

for

defaults

leads

to

the

well

known

Yale

shooting

problem

But

even

if

this

is

solved

e.g.

by

means

of

a

temporal

prioritization

other

strange

effects

remain

sometime

conditions

are

delayed

forever

disjunctive

postconditions

are

not

treated

in

the

intended

way

and

incomplete

information

is

not

supported

In

this

paper

we

show

how

to

solve

these

problems

by

means

of

a

new

default

semantics

based

on

the

notion

of

formula

instances

-LSB-

-RSB-

S.

Brass

On

the

Semantics

of

Supernormal

Defaults

In

R.

Bajcsy

-LRB-

ed

-RRB-

International

Joint

Conference

on

Artificial

Intelligence

-LRB-

Vol

-RRB-

Morgan

Kaufmann

Publishers

-LCB-

Our

goal

is

to

clarify

which

nonmonotonic

consequence

relation

j

is

given

by

a

set

of

supernormal

defaults

i.e.

defaults

of

the

form

true

ffi

ffi

There

are

in

fact

a

number

of

proposals

for

j

-LRB-

e.g.

the

skeptical

and

the

credulous

semantics

-RRB-

In

this

paper

we

look

at

the

space

of

all

possible

default

semantics

and

try

to

characterize

the

known

ones

by

their

properties

especially

the

valid

deduction

rules

For

instance

it

seems

reasonable

to

require

that

any

useful

semantics

should

coincide

with

the

original

CWA

if

this

is

consistent

We

might

also

want

to

allow

proofs

by

case

analysis

Then

we

get

the

skeptical

semantics

-LRB-

assuming

some

other

very

natural

deduction

rules

-RRB-

Our

results

are

in

fact

completeness

proofs

for

natural

deduction

systems

based

on

different

default

semantics

-LSB-

-RSB-

S.

Brass

Efficient

Query

Evaluation

in

Disjunctive

Deductive

Databases

Institut

f?ur

Informatik

Universit?at

Hannover

Hannover

It

is

known

that

bottom-up

query

evaluation

can

be

extended

to

work

with

disjunctive

facts

but

there

seems

to

be

the

common

assumption

that

it

is

much

too

inefficient

for

practical

applications

In

this

paper

we

improve

the

extended

bottom-up

evaluation

by

making

the

resolvable

literal

in

a

disjunctive

fact

unique

In

many

cases

this

reduces

an

exponential

behaviour

to

a

polynomial

one

We

introduce

the

notion

of

disjunction

types

formalizing

which

predicates

can

appear

together

in

a

disjunction

This

information

is

needed

to

generalize

implementation

techniques

based

on

the

predicate

dependency

graph

e.g.

to

determine

a

sequence

for

the

evaluation

of

the

rules

These

two

ideas

are

utilized

in

a

translation

of

disjunctive

rules

into

Horn

clauses

with

some

list-valued

arguments

This

shows

that

at

least

the

addition

of

a

few

disjunctive

rules

to

an

otherwise

Horn

database

does

not

destroy

the

possibility

of

efficient

query

evaluation

-LSB-

-RSB-

S.

Brass

Deduction

with

Supernormal

Defaults

In

G.

Brewka

K.

Jantke

P.

Schmitt

-LRB-

eds

-RRB-

Nonmonotonic

and

Inductive

Logic

Second

International

Workshop

LNCS

-LRB-

LNAI

-RRB-

Springer-Verlag

Berlin

-LCB-

In

this

paper

we

consider

supernormal

defaults

-LSB-

Poole

-RSB-

with

a

strict

partial

order

defining

their

priorities

-LSB-

Brewka

-RSB-

We

investigate

their

relation

to

minimal

or

preferential

entailment

and

show

that

the

semantics

given

in

-LSB-

Brewka

-RSB-

has

to

be

modified

in

order

to

be

equivalent

to

a

preferential

model

approach

Concerning

the

multiple

extension

problem

we

introduce

the

careful

view

as

an

alternative

to

the

credulous

and

skeptical

one

which

is

needed

to

handle

the

generalized

closed

world

assumption

-LSB-

Minker

-RSB-

within

this

framework

Given

this

declarative

semantics

of

such

default

theories

we

will

present

a

deduction

algorithm

for

query

answering

Compared

to

other

approaches

the

algorithm

is

quite

efficient

and

general

Especially

it

is

able

to

generate

disjunctive

answers

to

support

the

credulous

skeptical

and

careful

view

and

to

cut

fruitless

search

paths

early

In

order

to

check

the

applicability

of

defaults

as

soon

as

possible

we

introduce

the

notion

of

a

partial

extension

-LSB-

-RSB-

M.

Dionisio

S.

Brass

M.

Ryan

Reasoning

about

Extensions

In

U.

W.

Lipeck

G.

Koschorreck

-LRB-

eds

-RRB-

Proceedings

of

the

International

Workshop

on

Information

Sys

tems

-LCB-

Correctness

and

Reusability

-LRB-

IS-CORE

-RRB-

Informatik-Berichte

Univer

sit?at

Hannover

Hannover

-LCB-

Conclusions

can

be

drawn

from

incomplete

or

inconsistent

specifications

by

separating

the

corresponding

information

in

two

sorts

the

facts

known

for

sure

and

others

that

being

not

certain

are

plausible

and

will

be

used

to

extend

the

former

This

approach

is

formalized

in

Default

Logic

Among

the

conclusions

of

such

an

specification

there

may

be

properties

that

are

derived

from

facts

know

for

sure

other

derived

from

plausible

facts

and

even

other

derived

using

inconsistent

information

To

these

different

sorts

of

conclusions

correspond

different

degrees

of

credibility

It

is

possible

to

accept

or

reject

some

more

doubtful

conclusions

by

choosing

the

type

of

consequences

-LRB-

credulous

or

skeptical

for

example

-RRB-

that

are

of

interest

in

each

case

There

is

however

no

consequence

relation

that

in

a

uniform

way

allows

to

express

the

different

strength

of

those

conclusions

In

order

to

achieve

such

a

goal

we

need

to

enlarge

the

language

where

the

consequences

of

a

specification

are

written

For

the

simple

case

of

specifications

written

in

propositional

logic

we

will

present

a

modal

logic

consequence

relation

that

is

able

to

express

the

different

nature

of

the

consequences

of

the

original

specification

The

generalization

of

this

consequence

relation

to

modal

specifications

is

cumulative

-LSB-

-RSB-

M.

Dionisio

S.

Brass

M.

Ryan

U.

W.

Lipeck

Reasoning

about

Extensions

In

Working

Notes

from

the

Dutch/German

Workshop

on

Nonmonotonic

Reasoning

Techniques

and

Their

Applications

Part

RWTH

Aachen

Supernormal

default

theories

induce

a

preference

relation

on

the

models

of

their

axioms

We

view

this

preference

relation

as

a

modal

model

In

this

way

important

properties

of

propositional

default

theories

are

shown

to

be

expressible

by

truth

of

modal

formulas

in

the

corresponding

preference

relation

The

properties

thus

expressed

include

but

are

not

limited

to

propositional

credulous

and

skeptical

consequence

of

a

default

theory

and

any

boolean

combination

of

these

We

generalize

this

framework

to

a

modal

non-monotonic

and

cumulative

consequence

relation

The

consequences

of

the

modal

translation

of

a

default

theory

are

precisely

the

modal

formulas

that

hold

in

its

preference

relation

-LSB-

-RSB-

M.

Gertz

U.

W.

Lipeck

Deriving

Integrity

Maintaining

Triggers

from

Transition

Graphs

In

A.

Elmagarmid

E.

Neuhold

-LRB-

eds

-RRB-

Proceedings

of

the

IEEE

CS

Inter

national

Conference

on

Data

Engineering

IEEE

Computer

Society

Press

-LCB-

Modern

approaches

to

integrity

monitoring

suggest

to

generate

triggers

from

constraints

as

part

of

database

design

and

to

utilize

constraint

simplification

techniques

for

trigger

optimization

Such

proposals

however

have

been

restricted

to

static

conditions

which

constrain

single

states

only

In

this

paper

we

show

how

to

derive

triggers

from

dynamic

integrity

constraints

which

describe

properties

of

state

transitions

or

state

sequences

and

which

can

be

specified

by

formulae

in

temporal

logic

Such

constraints

can

equivalently

be

transformed

into

transition

graphs

which

describe

such

life

cycles

of

database

objects

that

are

admissible

with

respect

to

the

constraints

Nodes

correspond

to

situations

in

life

cycles

and

edges

give

the

-LRB-

changing

-RRB-

conditions

under

which

a

change

into

another

situation

is

allowed

If

object

situations

are

stored

integrity

maintaining

triggers

can

be

generated

from

transition

graphs

for

all

situations

and

all

critical

database

operations

Additionally

new

simplification

techniques

can

be

developed

by

identifying

characteristic

preconditions

in

the

graphs

and

by

utilizing

invariants

under

database

operations

Maintenance

of

situations

can

be

supported

by

triggers

as

well

-LSB-

-RSB-

M.

Gertz

Integrit?atssicherung

in

aktiven

Datenbanken

In

B.

Thalheim

-LRB-

ed

-RRB-

Grund

lagen

von

Informationssystemen

Tagung

des

Arbeitskreises

der

GI

Datenbanken

v.

in

Graal-M

uritz

Berichte

FB

Informatik

Universit?at

Rostock

Rostock

-LSB-

-RSB-

M.

Gertz

On

Specifying

the

Reactive

Behavior

on

Constraint

Violations

Informatik

Berichte

Institut

f?ur

Informatik

Universit?at

Hannover

Hannover

Recent

approaches

to

integrity

enforcement

in

active

databases

suggest

not

only

to

check

for

inconsistencies

by

triggers

but

also

to

utilize

triggers

to

perform

repair

actions

on

constraint

violations

Typically

respective

repairing

triggers

are

derived

automatically

from

constraint

specifications

following

almost

fixed

derivation

strategies

However

in

order

to

incorporate

more

semantic

knowledge

of

the

application

these

approaches

often

require

refinements

or

even

revisions

of

already

derived

integrity

checking

and

inconsistency

repairing

triggers

by

the

designer

In

this

paper

we

argue

that

analyzing

and

specifying

repair

actions

on

constraint

violations

should

be

also

a

design

task

and

exclusively

be

carried

out

in

the

conceptual

design

For

this

purpose

we

provide

a

declarative

specification

language

for

repair

actions

on

inconsistencies

with

an

operational

semantics

suitable

to

express

most

of

the

designers

intentions

on

the

behavior

on

constraint

violations

We

describe

a

design

methodology

for

reaction

specifications

and

show

how

integrity

checking

and

inconsistency

repairing

triggers

can

be

derived

from

these

specifications

-LSB-

-RSB-

G.

Koschorreck

U.

W.

Lipeck

Integrit?atssicherung

durch

lokale

Methoden

In

H.

Mayr

R.

Wagner

-LRB-

eds

-RRB-

Objektorientierte

Methoden

f?ur

Informationssysteme

Fachtagung

EMISA

Klagenfurt

Juni

Informatik

aktuell

Springer-Verlag

Berlin

-LCB-

Aufgabe

des

Datenbank-Entwurfs

ist

es

ein

Modell

der

realen

Welt

zu

entwerfen

Neben

der

Entwicklung

ad

aquater

Speicherstrukturen

kommt

dabei

der

Ber

ucksichtigung

von

Integrit

atsbedingungen

eine

zentrale

Bedeutung

zu

Um

sp

ater

die

Einhaltung

von

Integrit

atsbedingungen

sicherstellen

zu

k

onnen

m

ussen

sie

bereits

zur

Entwurfszeit

spezifiziert

werden

Da

jedoch

auch

Datenbankanwendungen

dem

zeitlichen

Wandel

unterliegen

mu

eine

Erweiterung

sowohl

des

Schemas

als

auch

der

zugeh

origen

Integrit

atsbedingungen

m

oglich

sein

Betrachtet

man

die

konzeptionellen

Objekte

die

Objekte

der

realen

Welt

repr

asentieren

auch

als

die

Einheiten

der

Integrit

atssicherung

so

kann

die

Uberwachung

von

Integrit

atsbedingungen

objekt-lokal

durchgef

uhrt

werden

Statt

der

Transaktionen

sorgen

dann

-LRB-

dynamisch

modifizierbare

-RRB-

Methoden

f

ur

die

Einhaltung

der

Integrit

atsbedingungen

-LSB-

-RSB-

G.

Koschorreck

U.

W.

Lipeck

Objekt-Beziehungen

Spezifikation

und

In

tegrit?atssicherung

Institut

f?ur

Informatik

Universit?at

Hannover

Hannover

In

terner

Bericht

vorgestellt

Workshop

Strukturierte

Objekte

Fachtagung

Sept.

in

Berlin

F?ur

komplexe

Anwendungen

ist

es

erforderlich

Beziehungen

zwischen

Objekten

verschiedener

Klassen

ad?aquat

beschreiben

zu

k?onnen

Ein

wesentliches

Charakteristikum

solcher

Beziehungen

ist

da

s

das

Verhalten

der

daran

beteiligten

Objekte

eingeschr?ankt

wird

Beziehungsspezifikationen

werden

als

den

Klassendefinitionen

gleichberechtigt

angesehen

und

dienen

dazu

die

Struktur

und

die

Restriktionen

f?ur

die

beteiligten

Objekte

zu

beschreiben

Die

Integrit?atsbedingungen

f?ur

Beziehungen

sind

dann

an

einer

Stelle

zusammengefa

st.

Hier

wird

einerseits

festgelegt

unter

welchen

Bedingungen

Objekte

in

eine

Beziehung

aufgenommen

werden

d?urfen

und

andererseits

welchen

Einschr?ankungen

beteiligte

Objekte

unterliegen

Um

eine

effiziente

Uberwachung

solcher

Integrit?atsbedingungen

zu

erm?oglichen

soll

die

Uberwachung

m?oglichst

objektlokal

durchgef?uhrt

werden

Zum

einen

k?onnen

dazu

Techniken

der

differentiellen

Integrit?ats?uberwachung

angewandt

werden

zum

anderen

ist

es

sinnvoll

den

Methodenaufrufmechanismus

f?ur

Objekte

so

zu

modifizieren

da

s

je

Objekt

ein

Methodenkontext

existiert

der

die

relevanten

Integrit?atspr?ufungen

f?ur

das

Objekt

enth?alt

So

kann

sichergestellt

werden

da

s

bestehende

Klassen

auch

in

neue

Beziehungen

eingebunden

werden

k?onnen

ohne

die

Klassendefinitionen

ver?andern

zu

m?ussen

-LSB-

-RSB-

G.

Koschorreck

Integrit?atssicherung

durch

zusammengesetzte

Objekte

In

W.

Stucky

A.

Oberweis

-LRB-

eds

-RRB-

Datenbanksysteme

in

B?uro

Technik

und

Wissenschaft

Informatik

aktuell

Springer-Verlag

Berlin

-LCB-

-LSB-

-RSB-

U.

W.

Lipeck

G.

Koschorreck

-LRB-

eds

-RRB-

Proceedings

of

the

International

Workshop

on

Information

Systems

-LCB-

Correctness

and

Reusability

-LRB-

IS-CORE

-RRB-

Informatik

Berichte

Universit?at

Hannover

Hannover

A

few

papers

are

available

in

the

-LSB-

-RSB-

U.

W.

Lipeck

B.

Thalheim

-LRB-

eds

-RRB-

Modelling

Database

Dynamics

-LRB-

Selected

Papers

from

the

Fourth

International

Workshop

on

Foundations

of

Models

and

Languages

for

Data

and

Objects

Volkse

Oct.

-RRB-

Workshops

in

Computing

Springer-Verlag

London

-LSB-

-RSB-

S.

Brass

U.

W.

Lipeck

Generalized

Bottom-Up

Query

Evaluation

In

A.

Pirotte

C.

De

lobel

G.

Gottlob

-LRB-

eds

-RRB-

Advances

in

Database

Technology

Proceedings

EDBT

Lecture

Notes

in

Computer

Science

Springer-Verlag

Berlin

-LCB-

Our

goal

is

to

generalize

the

well

known

bottom-up

set-oriented

query

evaluation

for

deductive

databases

in

two

aspects

First

we

consider

arbitrary

clauses

as

rules

in

the

database

not

only

Horn

clauses

or

clauses

with

stratified

negation

This

allows

to

represent

disjunctive

information

in

the

database

as

well

as

in

answers

to

queries

We

utilize

relations

for

modelling

sets

of

disjunctive

facts

and

operations

of

the

corresponding

relational

algebra

for

computing

consequences

and

answers

Thus

our

algorithm

should

be

of

practical

importance

for

applying

database

techniques

in

generalized

deductions

Second

we

parameterize

the

implicit

database

completion

which

underlies

query

evaluation

The

classical

rule

for

Horn

clause

databases

which

only

assumes

the

negation

of

facts

not

implied

by

the

database

is

not

applicable

to

disjunctive

databases

Moreover

the

choice

of

completion

often

depends

on

the

intended

application

Therefore

we

allow

ftp.informatik.uni-hannover

de/papers/ISCORE

Workshop/index

ISCORE.html

the

specification

of

arbitrary

clauses

as

defaults

and

we

extend

our

algorithm

to

consider

such

general

defaults

-LSB-

-RSB-

S.

Brass

Defaults

in

deduktiven

Datenbanken

Dissertation

FB

Mathematik

Univer

sit?at

Hannover

Hannover

-LSB-

only

small

number

of

copies

available

-RSB-

The

goal

of

this

thesis

is

a

theory

of

defaults

in

deductive

databases

Deductive

databases

store

formulae

which

describe

facts

corresponding

to

conventional

database

information

rules

for

deducing

further

information

and

indefinite

information

In

the

proof-theoretic

view

the

query

evaluation

consists

of

computing

consequences

of

the

stored

formulae

During

this

process

certain

formulae

can

be

assumed

as

defaults

if

no

contradicting

information

is

explicitly

given

Usually

defaults

are

used

to

evaluate

negated

literals

But

also

inheritance

in

object-oriented

approaches

and

other

knowledge

representation

formalisms

can

be

described

by

means

of

defaults

This

thesis

is

concerned

with

two

problem

areas

First

we

try

to

clarify

the

semantics

of

defaults

and

second

we

contribute

to

the

algorithmic

foundations

of

query

evaluation

Concerning

the

semantics

we

introduce

a

general

and

abstract

framework

and

discuss

various

alternatives

in

this

setting

Especially

we

characterize

the

expressiveness

of

the

minimal

model

approach

introduce

the

careful

closed

world

assumption

show

that

both

are

extremal

semantics

with

certain

properties

and

demonstrate

previously

unknown

defects

of

the

constructive

semantics

of

partially

ordered

defaults

With

respect

to

the

algorithmic

foundations

we

give

a

bottom-up

and

a

top-down

procedure

for

reasoning

with

explicit

defaults

There

seems

to

be

no

such

bottom-up

algorithm

in

the

literature

and

the

top-down

approach

has

the

advantage

over

previous

proposals

that

it

is

able

to

test

the

applicability

of

defaults

as

soon

as

possible

-LSB-

-RSB-

S.

Brass

Logic

Programs

Viewed

as

Modular

Specifications

Internal

Report

Institut

f?ur

Informatik

Universit?at

Hannover

Hannover

In

this

paper

we

add

a

module

system

to

supernormal

default

specifications

-LRB-

which

have

a

circumscription-like

minimal

model

semantics

-RRB-

Our

intention

is

to

formalize

that

certain

rules

define

certain

elementary

facts

we

do

not

consider

the

more

syntactical

side

of

modules

-LRB-

such

as

the

hiding

of

names

-RRB-

Logic

programs

can

be

naturally

translated

into

this

system

by

taking

the

head

literal

as

the

defined

part

of

a

rule

Our

main

results

are

criteria

for

the

equivalence

of

a

logic

program

and

a

modular

specification

Our

approach

explicitly

contains

the

module

information

given

by

logic

programming

rules

so

it

should

lead

to

a

better

understanding

of

their

semantics

Additionally

it

can

be

seen

as

a

common

generalization

of

logic

programming

and

supernormal

default

logic

it

supports

the

knowledge

representation

features

of

both

-LSB-

-RSB-

S.

Brass

A

Theorem

Prover

for

Prioritized

Supernormal

Defaults

Institut

f?ur

Infor

matik

Universit?at

Hannover

Hannover

We

present

a

top-down

theorem

prover

for

arbitrary

clauses

and

defaults

of

the

form

true

ffi

ffi

-LRB-

supernormal

defaults

-RRB-

with

priorities

This

especially

allows

to

specify

the

perfect

model

semantics

for

stratified

programs

but

it

includes

also

disjunctions

classical

negation

and

more

general

defaults

than

the

usual

negations

In

this

paper

we

concentrate

on

the

handling

of

the

priorities

and

consider

only

the

credulous

approach

to

multiple

extensions

But

the

ideas

from

-LSB-

Br

-RSB-

can

be

used

to

get

the

skeptical

and

the

careful

semantics

corresponding

to

prioritized

circumscription

and

an

extension

of

the

GCWA

The

most

interesting

aspect

of

our

work

is

that

we

are

able

to

incrementally

check

the

applicability

of

the

defaults

during

the

main

proof

-LRB-

via

our

notion

of

partial

extensions

-RRB-

Other

theorem

provers

for

prioritized

circumscription

-LSB-

-RSB-

had

to

postpone

this

test

into

a

second

phase

So

our

approach

seems

to

be

closer

to

the

usual

negation

as

failure

rule

which

evaluates

negated

literals

when

they

occur

in

the

proof

A

prototype

of

the

theorem

prover

has

been

implemented

in

Prolog

-LSB-

-RSB-

M.

Gertz

Deriving

Integrity

Constraints

Maintaining

Triggers

from

Transition

Graphs

In

U.

W.

Lipeck

R.

Manthey

-LRB-

eds

-RRB-

Kurzfassungen

des

GI-Workshops

Grundla

gen

von

Datenbanken

-LRB-

Barsinghausen

-RRB-

Technical

Report

ECRC

M?unchen

-LCB-

-LSB-

not

available

-RSB-

-LSB-

-RSB-

U.

W.

Lipeck

R.

Manthey

-LRB-

eds

-RRB-

Kurzfassungen

des

GI-Workshops

Grundlagen

von

Datenbanken

-LRB-

Barsinghausen

-RRB-

Technical

Report

ECRC

M?unchen

-LSB-

-RSB-

U.

W.

Lipeck

Integrit?atszentrierter

Datenbank-Entwurf

EMISA-Forum

-LRB-

-RRB-

-LCB-

In

diesem

Beitrag

wird

die

zentrale

phasen?ubergreifende

Rolle

diskutiert

die

die

Ber?ucksichtigung

von

Integrit?at

beim

Entwurf

von

zuverl?assigen

DatenbankAnwendungssystemen

spielt

-LRB-

bzw

spielen

sollte

-RRB-

Vielf?altige

Beispiele

zeigen

da

s

DB-Entwurf

neben

der

Modellierung

von

DB-Strukturen

die

Aufstellung

von

Integrit?atsbedingungen

verschiedener

Arten

sowie

vor

allem

deren

Transformation

in

uberwachbare

Elemente

wie

strukturelle

Integrit?atsbedingungen

und

Trigger

beinhaltet

-LSB-

-RSB-

U.

W.

Lipeck

Integrit?atszentrierter

Datenbank-Entwurf

-LRB-

Kurzfassung

-RRB-

Datenbank

Rundbrief

-LRB-

-RRB-

-LCB-

-LSB-

not

available

-RSB-

-LSB-

-RSB-

S.

Brass

U.

W.

Lipeck

Semantics

of

Inheritance

in

Logical

Object

Specifications

In

C.

Delobel

M.

Kifer

Y.

Masunaga

-LRB-

eds

-RRB-

Deductive

and

Object-Oriented

Databases

Proceedings

DOOD

Lecture

Notes

in

Computer

Science

Springer-Verlag

Berlin

-LCB-

Our

goal

is

to

integrate

the

paradigms

of

object-oriented

structuring

and

of

rule-based

specifications

for

databases

In

this

paper

we

consider

hierarchical

specifications

of

objects

and

object

types

with

attributes

defined

by

logical

rules

and

we

explain

their

local

-LRB-

single

object

-RRB-

semantics

as

well

as

their

composite

-LRB-

object

society

-RRB-

semantics

In

order

to

allow

inheritance

with

exceptions

-LRB-

overriding

-RRB-

even

for

rules

the

defining

formulas

are

interpreted

like

defaults

of

different

priorities

corresponding

to

levels

in

the

object

type

hierarchy

Here

minimal

model

semantics

known

from

default

reasoning

in

artificial

intelligence

or

from

database

completions

can

be

utilized

but

must

be

modified

to

respect

object-oriented

issues

in

particular

locality

We

prove

that

intended

models

exist

for

object

and

composite

specifications

under

natural

conditions

even

if

general

clauses

are

used

as

defaults

-LSB-

-RSB-

S.

Brass

U.

W.

Lipeck

Zur

Semantik

von

Vererbung

in

logischen

Objektspezifika

tionen

In

M.

H.

Scholl

-LRB-

ed

-RRB-

Grundlagen

von

Datenbanken

Kurzfassungen

des

GI-Workshops

Volkse

ETH

Z?urich

Z?urich

-LSB-

not

available

-RSB-

-LSB-

-RSB-

S.

Brass

M.

Ryan

U.

W.

Lipeck

Hierarchical

Defaults

in

Specifications

In

G.

Saake

A.

Sernadas

-LRB-

eds

-RRB-

Information

Systems

Correctness

and

Reusability

Workshop

IS

CORE

Informatik-Bericht

TU

Braunschweig

Braunschweig

-LCB-

The

goal

of

this

paper

is

to

explain

the

usage

and

semantics

of

hierarchical

defaults

in

logical

specifications

We

discuss

the

usefulness

of

defaults

for

different

specification

scenarios

like

specialization

aggregation

explanation

revision

etc.

and

we

illustrate

a

selection

of

them

by

examples

To

understand

defaults

formally

we

introduce

a

general

framework

parameterized

on

the

underlying

logical

institution

extended

by

an

instantiation

mechanism

for

formulae

It

is

shown

that

hierarchical

defaults

have

intended

models

if

the

extended

institution

is

compact

As

an

example

for

a

non-standard

logic

we

give

the

semantics

of

defaults

in

the

multi-modal

object

calculus

of

the

IS-CORE

project

To

structure

and

compose

specifications

with

defaults

default-preserving

specification

morphisms

are

defined

and

corresponding

colimit

constructions

are

sketched

-LSB-

-RSB-

M.

Erwig

U.

W.

Lipeck

A

Functional

DBPL

Revealing

High

Level

Optimizations

In

P.

Kanellakis

J.

Schmidt

-LRB-

eds

-RRB-

Database

Programming

Languages

The

Third

In

ternational

Workshop

-LRB-

-RRB-

Morgan

Kaufmann

Publishers

San

Mateo

CA

-LCB-

We

present

a

functional

DBPL

in

the

style

of

FP

that

facilitates

the

definition

of

precise

semantics

and

opens

up

opportunities

for

far-reaching

optimizations

The

language

is

integrated

into

a

functional

data

model

which

is

extended

by

arbitrary

type

hierarchies

and

complex

objects

Thus

we

are

able

to

provide

the

clarity

of

FP-like

programs

together

with

the

full

power

of

semantic

data

modelling

To

give

an

impression

of

the

special

facilities

for

optimizing

functional

database

languages

we

point

out

some

laws

not

presented

before

which

enable

access

path

selection

already

on

the

algebraic

level

of

optimization

The

algebraic

way

of

access

path

optimization

also

gives

some

new

insights

into

optimization

strategies

-LSB-

-RSB-

G.

Koschorreck

Eine

Algebra

f?ur

das

EER-Modell

In

M.

H.

Scholl

-LRB-

ed

-RRB-

Grundla

gen

von

Datenbanken

Kurzfassungen

des

GI-Workshops

Volkse

ETH

Z?urich

Z?urich

-LCB-

-LSB-

not

available

-RSB-

-LSB-

-RSB-

U.

W.

Lipeck

H.

Zhou

Monitoring

Dynamic

Integrity

Constraints

on

Finite

State

Se

quences

and

Existence

Intervals

In

J.

G?oers

A.

Heuer

G.

Saake

-LRB-

eds

-RRB-

Third

Workshop

on

Foundations

of

Models

and

Languages

for

Data

and

Objects

Informatik-Bericht

TU

Clausthal

Clausthal

-LCB-

Correct

database

behaviour

in

the

course

of

time

can

be

specified

by

requiring

dynamic

integrity

constraints

These

constraints

can

be

expressed

as

temporal

logic

formulae

which

however

usually

are

interpreted

in

infinite

state

sequences

Since

in

practice

only

a

partial

finite

prefix

of

an

infinite

sequence

is

known

notions

of

partial

admissibility

of

finite

sequences

with

respect

to

constraints

have

been

introduced

Admissibility

can

be

checked

on

each

state

transition

by

following

corresponding

paths

in

transition

graphs

which

can

be

constructed

for

arbitrary

temporal

formulae

In

this

paper

we

modify

temporal

logic

and

transition

graphs

as

introduced

in

our

former

work

by

giving

them

an

interpretation

in

the

empty

state

sequence

so

that

the

theory

can

be

extended

to

complete

finite

sequences

Since

practical

dynamic

constraints

are

to

refer

to

database

objects

only

during

their

existence

intervals

this

extension

is

utilized

to

handle

integrity

checks

on

the

deletion

of

objects

-LSB-

-RSB-

S.

Brass

Beginnings

of

a

Theory

of

General

Database

Completions

In

S.

Abiteboul

P.

C.

Kanellakis

-LRB-

eds

-RRB-

ICDT

Third

International

Conference

on

Database

The

ory

Lecture

Notes

in

Computer

Science

Springer-Verlag

Berlin

-LCB-

Ordinary

logical

implication

is

not

enough

for

answering

queries

in

a

logic

database

since

especially

negative

information

is

only

implicitly

represented

in

the

database

state

Many

database

completions

have

been

proposed

to

remedy

this

problem

but

a

clear

understanding

of

their

properties

and

differences

is

still

needed

In

this

paper

a

general

framework

is

proposed

for

studying

database

completions

which

reveals

an

interesting

and

fruitful

relation

to

social

choice

theory

We

apply

our

framework

to

parameterized

forms

of

the

minimal

model

approach

and

the

closed

world

assumption

as

well

as

to

two

versions

of

the

default

logic

simple

defaults

with

constraints

and

normal

defaults

Thereby

the

relationship

between

these

important

classes

of

database

completions

is

clarified

In

particular

it

is

shown

that

the

GCWA

can

not

be

simulated

by

any

of

the

other

three

approaches

We

also

give

a

characterization

of

those

completions

which

can

be

represented

as

a

form

of

minimal

implication

The

whole

discussion

is

based

on

various

properties

of

database

completions

which

have

proven

useful

as

a

means

for

classifying

the

proposed

approaches

Finally

we

illustrate

the

applicability

of

general

database

completions

to

conventional

deductive

databases

by

means

of

transformation

-LSB-

-RSB-

S.

Brass

Allgemeine

Vervollst?andigungen

beim

Entwurf

von

Logik-Datenbanken

In

U.

W.

Lipeck

S.

Brass

G.

Saake

-LRB-

eds

-RRB-

Kurzfassungen

des

Workshops

Grundlagen

von

Datenbanken

Volkse

Juni

TU

Braunschweig

Informatik-Bericht

TU

Braunschweig

Braunschweig

-LSB-

not

available

-RSB-

-LSB-

-RSB-

H.-J

Cronau

A

Transaction

Concept

for

Deductive

Databases

-LRB-

Dissertation

-RRB-

PhD

the

sis

FB

Informatik

Universit?at

Dortmund

Dortmund

-LSB-

available

from

author

-RSB-

Transactions

were

originally

introduced

for

classical

database

systems

to

relieve

an

application

programmer

from

controlling

parallel

activities

of

several

users

on

shared

resources

and

from

taking

care

of

possible

system

malfunctioning

In

our

thesis

we

extend

the

traditional

transaction

concept

to

deductive

database

systems

We

start

by

providing

an

update

concept

for

such

systems

It

is

based

on

a

variant

of

modal

logics

called

dynamics

oriented

logic

The

corresponding

database

language

allows

for

specifying

arbitrary

complex

-LRB-

update

-RRB-

programs

and

-LRB-

update

-RRB-

queries

The

language

is

described

precisely

by

a

declarative

Kripke

semantics

and

by

an

algebraic

operational

semantics

using

Gurevich

's

concept

of

dynamic

algebras

We

continue

by

establishing

the

notion

of

a

deductive

database

transaction

From

a

userUs

point

of

view

a

transaction

may

be

regarded

as

a

combination

of

nondeterministic

problem

solving

and

deterministic

data

manipulation

In

view

of

the

latter

characterization

we

present

a

set

of

sufficient

functionality

criteria

to

decide

whether

an

execution

of

a

transaction

program

will

lead

to

a

unique

database

state

From

a

database

system

viewpoint

we

suggest

the

conception

of

a

transaction

as

a

general

nested

structure

A

nesting

structure

is

induced

by

the

observed

call

relationship

between

transaction

operations

at

various

levels

of

operational

abstraction

In

order

to

allow

for

more

flexible

control

of

transactions

we

extend

our

update

concept

Incremental

queries

facilitate

interactive

dynamic

generation

of

transactions

additional

control

actions

provide

a

means

to

specify

in

a

program

or

to

demand

interactively

the

commit

abort

or

alternative

execution

of

transactions

and/or

subtransactions

Concurrent

execution

of

transactions

formally

represented

by

socalled

computation

forests

requires

appropriate

concurrency

control

to

synchronize

parallel

access

to

shared

resources

We

develop

a

special

serializability

theory

for

transactions

running

in

deductive

database

systems

Our

investigations

are

based

on

a

general

theory

for

nested

transactions

with

possibly

order

preserving

conflict

serializability

of

computation

forests

as

correctness

criterion

Nondeterminism

in

program

execution

suggests

a

set

oriented

conflict

definition

leading

to

the

concepts

of

proper

and

potential

conflicts

between

operations

By

restricting

to

proper

conflicts

we

are

able

to

derive

dedicated

correctness

criteria

which

allow

for

a

larger

class

of

serializable

computation

forests

The

correctness

criteria

take

into

consideration

whether

or

not

parallelism

within

transactions

is

permitted

In

case

it

is

not

serializability

proofs

reduce

to

a

simple

acyclicity

test

of

a

certain

relation

If

operations

of

the

same

transaction

are

executed

in

parallel

the

binding

of

logical

variables

considered

as

a

new

kind

of

shared

resources

has

to

be

synchronized

Hence

variable

binding

conflicts

have

to

be

respected

by

our

correctness

criteria

We

then

study

some

practical

consequences

of

our

theoretical

work

Depending

on

a

user

profile

we

propose

suitable

levels

of

operational

abstraction

where

a

scheduler

may

be

located

Afterwards

several

practical

variants

of

predicate

oriented

conflict

tests

are

described

Finally

we

develop

a

nested

two-phase

locking

protocol

and

prove

it

correct

With

respect

to

online

recovery

-LRB-

i.e.

recovery

after

transaction

failures

-RRB-

it

is

shown

that

theoretical

aspects

of

online

recovery

can

be

fully

treated

within

the

serializability

theory

presented

so

far

From

a

practical

point

of

view

we

favour

logical

logging

to

prepare

for

recovery

An

implementation

of

a

recovery

mechanism

may

exploit

the

run-time

stack

of

an

interpreter

as

a

log

-LSB-

-RSB-

G.

Koschorreck

Kalk?ule

f?ur

Anfragen

und

Deduktionen

uber

komplexen

Objekten

Diplomarbeit

FB

Informatik

Universit?at

Dortmund

Dortmund

-LSB-

not

available

-RSB-

-LSB-

-RSB-

G.

Koschorreck

Ausdrucksf?ahigkeit

von

Kalk?ulen

und

Anfragesprachen

f?ur

komplexe

Objekte

In

U.

W.

Lipeck

S.

Brass

G.

Saake

-LRB-

eds

-RRB-

Kurzfassungen

des

Workshops

Grundlagen

von

Datenbanken

Volkse

Juni

TU

Braunschweig

Informatik

Bericht

TU

Braunschweig

Braunschweig

-LCB-

-LSB-

not

available

-RSB-

-LSB-

-RSB-

U.

W.

Lipeck

S.

Brass

G.

Saake

-LRB-

eds

-RRB-

Kurzfassungen

des

Workshops

Grundlagen

von

Datenbanken

Volkse

Juni

TU

Braunschweig

Informatik-Bericht

TU

Braunschweig

Braunschweig

-LSB-

available

from

G.

Saake

TU

Braunschweig

-RSB-

-LSB-

-RSB-

U.

W.

Lipeck

Transformation

of

Dynamic

Integrity

Constraints

into

Transaction

Spec

ifications

Theoretical

Computer

Science

-LRB-

-RRB-

-LCB-

Dynamic

database

behaviour

can

be

specified

by

dynamic

integrity

constraints

which

determine

admissible

sequences

of

database

states

and

by

transaction

specifications

which

induce

executable

sequences

Constraints

are

expressed

by

formulae

of

temporal

logic

whereas

transactions

are

defined

by

pre/postconditions

in

predicate

logic

This

article

presents

concepts

and

rules

for

transforming

dynamic

constraints

into

transaction

specifications

in

order

to

prepare

integrity

monitoring

by

transactions

At

first

such

transition

graphs

must

be

constructed

from

temporal

formulae

that

have

paths

corresponding

to

admissible

sequences

Then

these

graphs

are

utilized

to

refine

and

to

simplify

pre/postconditions

systematically

so

that

every

executable

state

sequence

will

become

admissible

too

-LRB-

Keywords

integrity

dynamic

constraints

temporal

logic

transition

graphs

transactions

pre

postconditions

monitoring

constraint

simplification

-RRB-

-LSB-

-RSB-

P.

ICE

Abschlussbericht

Werkzeuge

f?ur

den

integrit?atszentrierten

Entwurf

von

Datenbank-Anwendungssystemen

WS

Interne

berichte

und

skripten

Uni

Dortmund

FB

Informatik

Dortmund

-LSB-

-RSB-

S.

Brass

U.

W.

Lipeck

Specifying

Closed

World

Assumptions

for

Logic

Databases

In

J.

Demetrovics

B.

Thalheim

-LRB-

eds

-RRB-

MFDBS

Symposium

on

Mathematical

Fundamentals

of

Database

Systems

Lecture

Notes

in

Computer

Science

Springer

Verlag

Berlin

-LCB-

Closed

world

assumptions

-LRB-

CWAs

-RRB-

are

an

important

class

of

implicit

completions

for

logic

databases

We

present

a

new

general

definition

of

CWA

it

is

parameterized

so

that

known

and

new

versions

of

CWAs

can

be

derived

as

special

cases

Our

CWA

in

turn

instantiates

the

more

basic

notion

of

database

completion

and

satisfies

natural

properties

It

can

even

be

characterized

by

the

property

of

determining

maximal

completions

without

generating

too

much

new

information

We

study

syntactic

as

well

as

semantic

definitions

and

prove

them

to

be

equivalent

By

discussing

several

instances

of

CWAs

we

demonstrate

the

applicability

of

our

framework

to

database

specification

-LSB-

-RSB-

S.

Brass

Vervollst?andigung

von

Logikdatenbanken

Forschungsbericht

Fachbereich

Informatik

Universit?at

Dortmund

Dortmund

A

database

state

can

be

viewed

as

a

set

of

first

order

logic

formulae

Then

query

answering

is

done

by

deduction

from

this

set

Logical

implication

however

is

not

sufficient

to

give

all

intuitively

correct

answers

since

some

information

in

particular

negative

information

is

represented

only

implicitly

Several

completions

are

known

from

the

literature

which

help

to

formalize

the

implicit

assumptions

of

deductive

query

answering

e.g.

minimal

implication

circumscription

closed

world

assumptions

-LRB-

CWA

-RRB-

and

the

completed

data

base

-LRB-

CDB

-RRB-

The

purpose

of

this

report

is

to

give

an

extensive

and

unifying

survey

of

these

completions

-LRB-

excluding

answer

algorithms

-RRB-

To

this

end

a

new

and

very

general

framework

is

proposed

for

examining

such

completions

Above

all

a

catalog

of

properties

is

defined

which

are

proven

or

disproven

for

the

various

versions

Most

of

these

properties

have

been

extracted

from

known

results

but

some

are

new

All

the

proofs

are

given

-LSB-

-RSB-

S.

Brass

Spezifikation

von

Annahmen

der

geschlossenen

Welt

-LRB-

CWAs

-RRB-

In

H.-D

Ehrich

G.

Engels

M.

Gogolla

G.

Saake

-LRB-

eds

-RRB-

Abstracts

des

Workshops

Grundla

gen

von

Datenbanken

TU

Braunschweig

Informatik-Bericht

TU

Braunschweig

Braunschweig

-LSB-

not

available

-RSB-

-LSB-

-RSB-

S.

Brass

Remarks

on

First

Order

Circumscription

Unpublished

Research

Note

FB

Informatik

Universit?at

Dortmund

Dortmund

Circumscription

is

a

form

of

non-monotonic

inference

intended

to

formalize

common

sense

reasoning

-LRB-

-LSB-

-RSB-

-LSB-

-RSB-

-RRB-

Various

versions

have

been

defined

which

can

be

classified

into

first-order

and

second-order

Whereas

the

minimal

model

semantics

of

second

order

circumscription

is

thoroughly

investigated

the

order

relation

underlying

first

order

circumscription

has

only

recently

been

formally

defined

-LRB-

-LSB-

-RSB-

-LSB-

-RSB-

-RRB-

We

show

that

this

order

relation

is

not

well-founded

even

for

sets

of

Horn

clauses

This

leads

to

the

violation

of

a

very

natural

property

called

cumulation

in

-LSB-

-RSB-

or

idempotency

in

-LSB-

-RSB-

The

second

part

of

this

paper

is

devoted

to

the

problem

of

extra

free

variables

in

the

expressions

substituted

for

the

predicates

-LRB-

open

v.

closed

first

order

circumscription

-RRB-

We

prove

that

open

nonrecursive

circumscription

can

introduce

inconsistencies

-LRB-

this

question

originates

from

-LSB-

-RSB-

and

was

also

discussed

in

-LSB-

-RSB-

-RRB-

We

also

show

that

open

circumscription

is

unnecessary

for

sets

of

Horn

clauses

-LSB-

-RSB-

H.-D

Ehrich

M.

Gogolla

U.

W.

Lipeck

Algebraische

Spezifikation

abstrakter

Daten

typen

Teubner

Stuttgart

-LSB-

-RSB-

U.

W.

Lipeck

Dynamische

Integrit?at

von

Datenbanken

Grundlagen

der

Spezifikation

und

Uberwachung

Informatik-Fachberichte

Springer-Verlag

Berlin

In

database

design

not

only

the

static

structure

of

a

database

system

but

also

its

dynamic

behaviour

has

to

be

specified

In

order

to

determine

admissible

sequences

of

states

dynamic

integrity

constraints

are

given

Transactions

i.e.

basic

elements

of

application

programs

complementarily

induce

executable

state

sequences

This

book

presents

two

approaches

to

monitoring

dynamic

database

integrity

Theoretic

and

algorithmic

fundamentals

are

treated

as

well

as

impacts

on

design

Integrity

constraints

are

expressed

by

formulae

of

temporal

logic

whereas

transactions

are

defined

by

pre

postconditions

in

predicate

logic

Using

temporal

formulae

different

procedures

can

be

applied

to

construct

transition

graphs

whose

paths

correspond

to

admissible

state

sequences

On

the

one

hand

these

graphs

control

execution

of

a

universal

monitor

that

reduces

analysis

of

state

sequences

to

local

tests

in

states

On

the

other

hand

constraints

can

systematically

be

transformed

into

pre

postconditions

according

to

transition

graphs

such

that

each

executable

sequence

becomes

admissible

The

latter

approach

prepares

efficient

monitoring

by

transactions

and

supports

stepwise

specification

of

database

behaviour

-LRB-

Keywords

database

design

conceptual

schema

database

behaviour

dynamic

integrity

constraints

temporal

logic

transition

graphs

integrity

monitoring

transactions

pre

postconditions

-RRB-

-LSB-

-RSB-

U.

W.

Lipeck

Schrittweiser

Entwurf

von

Datenbankverhalten

durch

Transforma

tion

dynamischer

Intergrit?atsbedingungen

In

H.-D

Ehrich

G.

Engels

M.

Gogolla

G.

Saake

-LRB-

eds

-RRB-

Abstracts

des

Workshops

Grundlagen

von

Datenbanken

TU

Braun

schweig

Informatik-Bericht

TU

Braunschweig

Braunschweig

-LSB-

not

avail

able

-RSB-

-LSB-

-RSB-

G.

Saake

U.

W.

Lipeck

Using

Finite-Linear

Temporal

Logic

for

Specifying

Database

Dynamics

In

E.

B?orger

H.

Kleine

B?uning

M.

M.

Richter

W.

Sch?onfeld

-LRB-

eds

-RRB-

Com

puter

Science

Logic

CSL

Lecture

Notes

in

Computer

Science

Springer-Verlag

Berlin

-LCB-

-LSB-

-RSB-

S.

Brass

Vervollst?andigungen

f?ur

Logikdatenbanken

Diplomarbeit

Techn

Universit?at

Braunschweig

-LSB-

superseded

by

-RSB-

-LSB-

-RSB-

U.

W.

Lipeck

D.

Feng

Construction

of

Deterministic

Transition

Graphs

from

Dynamic

Integrity

Constraints

In

J.

v.

Leeuwen

-LRB-

ed

-RRB-

Graph-Theoretic

Concepts

in

Computer

Science

International

Workshop

WG

Lecture

Notes

in

Computer

Science

Springer-Verlag

Berlin

-LCB-

Here

systems

in

particular

database

systems

are

considered

whose

dynamic

behaviour

is

characterized

by

state

sequences

that

evolve

stepwise

and

whose

integrity

constraints

are

specified

by

means

of

temporal

logic

Monitoring

temporal

formulae

in

state

sequences

can

be

reduced

to

following

paths

in

transition

graphs

by

only

checking

nontemporal

edge

labels

in

each

state

This

paper

presents

an

algorithm

how

to

construct

deterministic

transition

graphs

from

temporal

formulae

in

a

bottom-up

way

corresponding

to

the

formula

structure

These

graphs

ensure

at

least

provisional

admissibility

of

system

behaviour

up

to

a

present

state

and

at

most

potential

admissibility

of

future

behaviour

Moreover

deterministic

graphs

have

considerable

advantages

over

general

transition

graphs

-LSB-

-RSB-

U.

W.

Lipeck

G.

Saake

Entwurf

von

Systemverhalten

durch

Spezifikation

und

Trans

formation

temporaler

Anforderungen

In

R.

Valk

-LRB-

ed

-RRB-

Proc

GI-Jahrestagung

Hamburg

Okt

Informatik-Fachberichte

Springer-Verlag

Berlin

-LCB-

Beim

Entwurf

von

reaktiven

Softwaresystemen

-LRB-

z.B.

Informationssystemen

-RRB-

sind

neben

der

Struktur

von

Zust?anden

auch

die

zul?assigen

zeitlichen

Entwicklungen

festzulegen

diese

lassen

sich

durch

Folgen

von

Zust?anden

charakterisieren

und

werden

durch

Anwendungsoperationen

induziert

In

dieser

Arbeit

wird

eine

Methode

f?ur

die

schrittweise

formale

Spezifikation

von

dynamischem

Systemverhalten

vorgestellt

Es

wird

eine

zweischichtige

Beschreibung

verwendet

die

einerseits

deskriptiv

Anforderungen

an

ganze

Zustandsfolgen

formuliert

in

temporaler

Logik

und

andererseits

Vor

Nachbedingungen

f?ur

die

einzelnen

Operationen

vorsieht

Nachdem

die

beiden

Spezifikationsteile

erst

komplement?ar

aufgestellt

werden

lassen

sich

dann

aus

den

temporalen

Anforderungen

korrekte

Objektlebensl?aufe

ableiten

und

graphisch

darstellen

Schlie

slich

werden

die

so

erhaltenen

Bedingungen

an

Zustands?uberg?ange

systematisch

in

verfeinerte

Vor

Nachbedingungen

transformiert

so

da

s

allein

die

Operationen

die

Zul?assigkeit

des

Systemverhaltens

gem?a

s

den

Anforderungen

garantieren

-LSB-

-RSB-

U.

W.

Lipeck

G.

Saake

Entwurf

von

Systemverhalten

durch

Spezifikation

und

Trans

formation

temporaler

Anforderungen

-LRB-

Kurzfassung

-RRB-

EMISA-Workshop

-LRB-

Tutzing

Nov.

-RRB-

-LSB-

-RSB-

U.

W.

Lipeck

Transformation

of

Dynamic

Integrity

Constraints

into

Transaction

Spec

ifications

In

M.

Gyssens

J.

Paredaens

D.

Van

Gucht

-LRB-

eds

-RRB-

ICDT

In

ternational

Conference

on

Database

Theory

Proceedings

Lecture

Notes

in

Computer

Science

Springer-Verlag

Berlin

-LCB-

-LSB-

extended

version

in

-RSB-

Dynamic

database

behaviour

can

be

specified

by

dynamic

integrity

constraints

which

determine

admissible

sequences

of

database

states

and

by

transaction

specifications

which

induce

executable

sequences

Constraints

are

expressed

by

formulae

of

temporal

logic

whereas

transactions

are

defined

by

pre/postconditions

in

predicate

logic

This

paper

presents

concepts

and

rules

for

transforming

dynamic

constraints

into

transaction

specifications

in

order

to

prepare

integrity

monitoring

by

transactions

At

first

such

transition

graphs

must

be

constructed

from

temporal

formulae

that

have

paths

corresponding

to

admissible

sequences

Then

these

graphs

are

utilized

to

refine

and

to

simplify

pre/postconditions

systematically

so

that

every

executable

state

sequence

becomes

admissible

too

-LRB-

Keywords

integrity

dynamic

constraints

temporal

logic

transition

graphs

transactions

pre

postconditions

monitoring

constraint

simplification

-RRB-

-LSB-

-RSB-

U.

W.

Lipeck

Zur

dynamischen

Integrit?at

von

Datenbanken

Grundlagen

der

Spezi

fikation

und

Uberwachung

Habilitationsschrift

Techn

Universit?at

Braunschweig

-LSB-

superseded

by

-RSB-

-LSB-

-RSB-

D.

S.

Feng

U.

W.

Lipeck

Deterministische

Uberwachung

temporaler

Formeln

Informatik-Bericht

TU

Braunschweig

Braunschweig

We

consider

systems

in

particular

database

systems

whose

dynamic

behaviour

is

characterized

by

state

sequences

that

evolve

stepwise

Integrity

constraints

can

be

specified

by

means

of

temporal

logic

In

order

to

monitor

validity

of

temporal

formulas

in

a

state

sequence

given

at

runtime

transition

graphs

are

used

This

report

presents

an

algorithm

to

construct

deterministic

transition

graphs

from

temporal

formulas

in

a

bottom-up

way

corresponding

to

the

formula

structure

Construction

and

application

of

such

graphs

show

considerable

advantages

over

general

transition

graphs

An

algorithm

analysis

confirms

that

the

constructed

graphs

are

suited

for

monitoring

provisional

validity

up

to

the

present

system

state

Finally

we

adapt

reduction

methods

for

transition

graph

so

that

even

potential

validity

in

future

system

behaviour

can

be

ensured

-LRB-

Keywords

system

behaviour

integrity

monitoring

dynamic

database

integrity

temporal

logic

deterministic

transition

graphs

-RRB-

-LSB-

-RSB-

U.

W.

Lipeck

G.

Saake

Monitoring

Dynamic

Integrity

Constraints

Based

on

Temporal

Logic

Information

Systems

-LRB-

-RRB-

-LCB-

Dynamic

integrity

constraints

are

used

to

specify

admissible

sequences

of

database

states

We

present

algorithmic

fundamentals

of

monitoring

constraints

expressed

in

temporal

logic

The

essential

means

are

finite

transition

graphs

which

can

be

constructed

from

temporal

formulas

by

utilizing

an

appropriate

normalform

To

ensure

admissibility

of

a

state

sequence

the

integrity

monitor

has

to

follow

a

corresponding

path

through

the

graph

and

to

check

certain

certain

nontemporal

conditions

in

each

state

these

conditions

are

provided

as

edge

labels

Thus

monitoring

dynamic

integrity

is

reduced

to

a

controlled

checking

of

static

integrity

All

errors

in

present

database

behaviour

are

detected

as

well

as

many

inevitable

future

errors

-LRB-

Keywords

database

integrity

dynamic

constraints

temporal

logic

integrity

monitoring

transition

graph

-RRB-

-LSB-

-RSB-

G.

Saake

U.

W.

Lipeck

Foundations

of

Temporal

Integrity

Monitoring

In

C.

e.

a.

Rolland

-LRB-

ed

-RRB-

Temporal

Aspects

in

Information

Systems

-LRB-

Proc

IFIP

Work

Conf

TAIS

-RRB-

North-Holland

Amsterdam

The

Netherlands

-LCB-

To

ensure

temporal

integrity

of

a

database

each

sequence

of

database

states

must

satisfy

given

constraints

We

present

basic

results

and

algorithms

for

monitoring

integrity

constraints

expressed

in

temporal

logic

The

essential

means

of

monitoring

are

finite

transition

graphs

which

can

be

constructed

from

arbitrary

propositional

temporal

formulas

For

a

current

state

sequence

an

integrity

monitor

has

to

follow

corresponding

paths

through

transition

graphs

and

to

check

certain

nontemporal

conditions

in

each

state

these

conditions

are

provided

as

edge

labels

Thus

monitoring

temporal

integrity

is

reduced

to

a

controlled

checking

of

static

integrity

so

that

all

errors

up

to

the

present

database

state

are

detected

-LSB-

-RSB-

H.-D

Ehrich

K.

Drosten

M.

Gogolla

U.

Lipeck

-LRB-

eds

-RRB-

Abstracts

of

the

Workshop

on

Specification

of

Abstract

Data

Types

TU

Braunschweig

Informatik-Bericht

TU

Braunschweig

Braunschweig

-LSB-

available

from

H.-D

Ehrich

TU

Brauschweig

-RSB-

-LSB-

-RSB-

U.

W.

Lipeck

K.

Neumann

Modelling

and

Manipulating

Objects

in

Geoscientific

Databases

In

S.

Spaccapietra

-LRB-

ed

-RRB-

Proceedings

of

the

International

Conference

on

Entity-Relationship

Approach

WG

-LRB-

Databases

-RRB-

ACM

IEEE

Dijon

France

-LCB-

This

paper

presents

a

database

interface

for

geoscientific

applications

It

is

based

on

a

geoobject

model

derived

from

an

extended

entity-relationship

model

so

that

geoscientific

objects

and

their

representation

in

maps

can

be

described

Special

datatypes

are

used

for

geometric

and

temporal

attributes

Then

a

database

language

is

introduced

which

integrates

object

model

and

datatypes

Queries

and

updates

can

be

formulated

by

mostly

descriptive

means

and

their

semantics

is

explainable

by

an

object

calculus

adapted

to

the

model

In

addition

standard

operations

like

map

construction

are

supported

-LSB-

-RSB-

U.

W.

Lipeck

G.

Saake

H.-D

Ehrich

Monitoring

Dynamic

Database

Integrity

by

Transition

Graphs

Technical

Report

TU

Braunschweig

Braunschweig

-LSB-

superseded

by

-RSB-

-LSB-

-RSB-

U.

W.

Lipeck

Stepwise

Specification

of

Dynamic

Database

Behaviour

In

C.

Zan

iolo

-LRB-

ed

-RRB-

Proceedings

of

the

ACM

SIGMOD

International

Conference

on

Man

agement

of

Data

SIGMOD

Record

ACM

Press

New

York

-LCB-

This

paper

presents

a

methodology

for

the

stepwise

specification

of

dynamic

database

behaviour

A

conceptual

schema

is

described

in

three

levels

data

objects

and

transactions

To

determine

which

sequences

of

database

states

are

admissible

integrity

constraints

on

objects

are

given

in

temporal

logic

Transactions

are

specified

by

pre/postcopnditions

to

produce

executable

state

sequences

In

order

to

guarantee

that

executable

state

sequences

already

become

admissible

integrity

constraints

are

completely

transformed

into

additional

pre/postconditions

We

introduce

general

rules

for

these

transformations

Thus

schema

specifications

can

be

refined

and

simplified

systematically

-LSB-

-RSB-

U.

W.

Lipeck

On

the

Semantics

of

the

Frame

Rule

-LRB-

Abstract

-RRB-

In

H.-D

Ehrich

K.

Drosten

M.

Gogolla

U.

Lipeck

-LRB-

eds

-RRB-

Abstracts

of

the

Workshop

on

Specification

of

Abstract

Data

Types

TU

Braunschweig

Informatik-Bericht

TU

Braunschweig

Braunschweig

-LSB-

not

available

-RSB-

-LSB-

-RSB-

U.

W.

Lipeck

H.-D

Ehrich

M.

Gogolla

Specifying

Admissibility

of

Dynamic

Database

Behaviour

Using

Temporal

Logic

In

A.

Sernadas

J.

Bubenko

A.

Olive

-LRB-

eds

-RRB-

Theoret

ical

and

Formal

Aspects

of

Information

Systems

-LRB-

Proc

IFIP

Work

Conf

TFAIS

-RRB-

North-Holland

Amsterdam

The

Netherlands

-LCB-

This

work

uses

temporal

logic

as

a

calculus

for

expressing

integrity

constraints

that

specifiy

admissibility

of

dynamic

database

behaviour

Formulas

are

interpreted

in

state

seqeunces

representing

dynamic

behaviour

Our

approach

incorporates

temporal

quantification

by

always

sometime

and

quantifiers

bounded

by

intervals

in

state

sequences

Moreover

dynamically

changing

domains

of

database

values

are

considered

We

then

use

special

kinds

of

formulas

as

a

language

for

dynamic

constraints

and

give

some

hints

how

to

specify

in

typical

situations

For

such

formulas

a

frame

for

monitoring

constraints

during

database

runtime

is

discussed

which

allows

to

characterize

admissibility

operationally

-LSB-

-RSB-

U.

W.

Lipeck

Schrittweise

Spezifikation

des

dynamischen

Verhaltens

von

Datenbanken

In

Proc

GI-Fachgespr

ach

Entwurf

von

Informationssystemen

Methoden

und

Modelle

-LRB-

Mai

Tutzing

-RRB-

-LCB-

-LSB-

-RSB-

I.

Ramm

K.

Neumann

U.

W.

Lipeck

H.-D

Ehrich

Eine

Benutzerschnittstelle

f?ur

geowissenschaftliche

Datenbanken

Technical

Report

TU

Braunschweig

Braun

schweig

-LSB-

out

of

print

-RSB-

-LSB-

-RSB-

H.-D

Ehrich

U.

W.

Lipeck

M.

Gogolla

Specification

Semantics

and

Enforcement

of

Dynamic

Database

Constraints

In

U.

Dayal

G.

Schlageter

L.

Seng

-LRB-

eds

-RRB-

Proceed

ings

of

the

International

Conference

on

Very

Large

Data

Bases

Morgan

Kaufmann

Publishers

Palo

Alto

CA

-LCB-

-LSB-

-RSB-

M.

Gogolla

K.

Drosten

U.

W.

Lipeck

H.-D

Ehrich

Algebraic

and

Operational

Seman

tics

of

Specifications

Allowing

Exceptions

and

Errors

Theoretical

Computer

Science

-LRB-

-RRB-

-LCB-

-LSB-

-RSB-

H.-D

Ehrich

U.

W.

Lipeck

Algebraic

Domain

Equations

Theoretical

Computer

Science

-LRB-

-RRB-

-LCB-

-LSB-

-RSB-

M.

Gogolla

K.

Drosten

U.

W.

Lipeck

H.-D

Ehrich

Algebraic

and

Operational

Seman

tics

of

Exceptions

and

Errors

In

Proc

GI-Conf

on

Theoretical

Computer

Science

Lecture

Notes

in

Computer

Science

GI

Springer-Verlag

Berlin

-LCB-

-LSB-

-RSB-

U.

W.

Lipeck

H.-D

Ehrich

Algebraic

Specification

of

Database

Constraints

-LRB-

Abstract

-RRB-

In

Workshop

on

Theory

and

Applications

of

Abstract

Data

Types

Uni

Passau

Bericht

Fakult?at

f?ur

Informatik

Universit?at

Passau

Passau

-LSB-

not

available

-RSB-

-LSB-

-RSB-

U.

W.

Lipeck

Ein

Algebraischer

Kalk?ul

f?ur

einen

Strukturierten

Entwurf

von

Daten

abstraktionen

-LRB-

Dissertation

-RRB-

Dissertation

Forschungsbericht

FB

Informatik

Uni

versit?at

Dortmund

Dortmund

-LSB-

-RSB-

U.

W.

Lipeck

Structuring

the

Design

of

Data

Abstractions

-LRB-

Abstract

-RRB-

In

K.

Indermark

J.

Loeckx

-LRB-

eds

-RRB-

Abstracts

of

the

Talks

at

the

Fourth

Int

Workshop

on

the

Semantics

of

Programming

Languages

in

Bad

Honnef

March

Bericht

A

Uni

Saarbr?ucken

Fachbereich

Saarbr?ucken

-LCB-

-LSB-

not

available

-RSB-

-LSB-

-RSB-

K.

Drosten

M.

Gogolla

H.-D

Ehrich

U.

Lipeck

A

Hierarchical

Approach

to

an

Operational

Semantics

for

Conditional

Algebraic

Specifications

Technical

Report

Abteilung

Informatik

Universit?at

Dortmund

Dortmund

-LSB-

-RSB-

M.

Gogolla

K.

Drosten

U.

Lipeck

H.-D

Ehrich

Algebraic

and

Operational

Seman

tics

of

Specifications

Allowing

Exceptions

and

Errors

Technical

Report

Abtlg

Informatik

Univ.

Dortmund

-LSB-

out

of

print

-RSB-

-LSB-

-RSB-

H.-D

Ehrich

U.

Lipeck

Algebraic

Domain

Equations

Technical

Report

Abteilung

Informatik

Universit?at

Dortmund

Dortmund

-LSB-

superseded

by

-RSB-

-LSB-

-RSB-

H.-D

Ehrich

U.

Lipeck

Proving

Implementations

Correct

Two

Alternative

Ap

proaches

In

S.

H.

Lavington

-LRB-

ed

-RRB-

Information

processing

Proc

of

IFIP

Congress

North-Holland

Amsterdam

The

Netherlands

-LCB-

-LSB-

-RSB-

U.

Lipeck

Zum

Begriff

der

Implementierung

in

der

Theorie

der

abstrakten

Daten

typen

Diplomarbeit

Abteilung

Informatik

Universit?at

Dortmund

Dortmund

-LSB-

not

available

-RSB-

-LSB-

-RSB-

B.

Losbichler

U.

Lipeck

P.

Siemon

Externe

Datenbest?ande

Eine

Einf?uhrung

f?ur

SIMULA-Anwender

Technical

Report

Abteilung

Informatik

Universit?at

Dortmund

Dortmund

-LSB-

out

of

print

-RSB-

disjunctive logic programming
non-monotonic reasoning
semantics and foundations