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Emerging Database Technologies

and Applications

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Progression of Database Technology

Future

Merging data models with

knowledge representation

Hybrid models

Client-server configuration

Parallel processing

Optical memories

MultimediaNatural languages

Speech input

Freehand text

Integrated database and

programming languages

Generalized presentation

managers

Distributed, heterogeneous

data and knowledge

processing with multimedia

information

Parallel database

management

1980s to Early 1990s

Semantic

Object-oriented

Logic

Faster PCs

Workstations

Database machines

Back ends

GraphicsMenus

Query-by-forms

Standardized SQL

4GL

Logic programming

Business graphics

Image output

Transaction processing

Knowledge processing

1970s to Mid-1980s

Relational

Mainframes

Minis

PCs

Query languagesForms

Embedded query

languages

Report generators

Information and

transaction processing

1960s to Mid-

1970sNetworkHierarchical

Mainframes

None

Procedural

Reports

Processing

data

Data Model

DatabaseHardware

User Interface

ProgramInterface

Presentationand Display

Processing

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Current Trends in Technology

Distributed, heterogeneous environments

Open systems

More functionality Parallel database management

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Next Generation of DBMSs

Active databases

Applications such as process control, powerdistribution/generation, workflow control, program

trading, battle management, patient monitoring are notwell served by passive DBMSs

conditions defined on states of the database must bemonitored and actions taken

active databases support condition monitoring

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Active Databases

Active DBMS

Queries and updates

External events

Actions

Specification of events andconditions to be monitored

Payoffs: No changes to applications DBMS optimizes rules Enhances DBMS functionality Meet the time-constrained

requirements of applications

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Issues in Active Databases

Efficiency

a large set of rules need to be managed and evaluatedefficiently

Modes of rule execution rules can be fired in an immediate, deferred, or detached

mode in regard to the original transaction

Data model extension

specifying events, conditions, and actions events:

database operations (insert, delete, modify)

temporal events (5 p.m. every day)

user- or application-generated events (hardware failure)

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Issues in Active Databases

Management of rules

ability to manipulate rules (add/delete/modify)

mechanisms for enabling and disabling rules or rule sets

Supporting DBMS functions

examples: constraint management, maintenance ofderived data, rule-based inferencing

Interaction with parts of DBMS

optimization of rules requires interaction with transactionmanager, object manager, and scheduler

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State of the Art in Active

Databases HiPAC (High Performance ACtive database system)

research project at Xerox

PROBE for battle management application (Computer

Corporation of America) Event/Trigger Mechanism (Univ. of Karlsruhe)

POSTGRES (Stonebraker, UC Berkeley)

Starburst project at IBM

Sybase supports simple triggers

InterBase does not impose most of the restrictions seen inSybase

ORACLE v. 7, INGRES, INFORMIX, etc. provide somedegree of rule and trigger support

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Multimedia Databases

Applications:

documents and records management

knowledge dissemination

education and training

marketing, advertising, retailing, travel

real-time control and monitoring

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Multimedia Databases

Multimedia IS are very complex; issues:

modeling, dealing with complex objects

design (conceptual, logical, physical) not researched yet

storage on standard devices presents problems

retrieval opens up many issues

performance problem solving efforts are experimental

Databases (fixed data structure) versus

information retrieval (text) perspectives Requirements of multimedia/hypermedia data

modeling and retrieval

query mechanism should have access to the links (?)

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Multimedia Databases

Indexing of images

automatic object identification

manual indexing

Open problems in text retrieval

Multimedia information systems promise to bringabout a marriage of the disciplines of informationretrieval and database management

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Spatial Database Management

The spatial semantics can be captured by threecommon representations:

solid representation

the space is divided into pieces

boundary representation

the spatial characteristics are represented by linesegments or boundaries

abstract representation

relationships with spatial semantics, such as ABOVE,NEAR, IS NEXT TO, BEHIND, are used to associate entities

The PROBE project provided support for spatialdata

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Temporal Database Management

An one-dimensional case of spatial information

Includes three types of support for time:

time points

time intervals

abstract relationships (before, after, during,simultaneously, concurrently, ...)

The history aspect of databases is important for

project management, patient histories,maintenance histories, etc.

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Temporal Database Management

A range of businesses (ex. finance, medical, legal,manufacturing) can benefit from quick access tohistorical and current data

Limitations of current databases:

data become valid at the time they are recorded; noprovision for distinguishing between transaction timeand valid time

no capability to preserve historical information Until recently, inefficient storage capabilities made

the temporal database concept not practical

WORM and compression technology made it

possible

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Tuple Time Stamping

EmpNo

33

33

45

45

Salary

20K

25K

27K

30K

Position

Typist

Secretary

Jr. Engineer

Sr. Engineer

Start time

12

25

28

38

End time

24

35

37

42

One proposed model is the Temporal RelationalModel

Attributes, relations are divided into time-varying andnon-time-varying

For time-varying relations, two timestamp attributes are

appended SQL is extended into Temporal SQL (TSQL)

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Open Problems

Reasoning with temporal information

Processing information over valid-time andtransaction-time databases

Mixing temporal processing with active anddeductive databases

Integrating temporal information overheterogeneous environments

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Update on Temporal DB Research

Recent Advances in Temporal Databases, J. Clifford and A. Tuzhilin,(Eds.), Proceedings of the International Workshop on TemporalDatabases, Zurich, Switzerland, 17-18 September 1995, Springer, 1995.X, 362 pp. 80 figs. Softcover $79.00 ISBN 3-540-19945-4

Papers cover a wide range of topics from the highly theoreticalthrough to reports on how temporal data bases can be used to solvereal problems

In addition to the technical papers, there are also summaries of twopanel discussions which assess the recently-completed TSQL2Language Design, and examine the need for additional research into

the development of TSQL3 Together these papers provide a comprehensive overview of the latest

research work into the area of temporal databases

Also see URL: http://www.jcc.com/sql_tmpr.html

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Extensible Database Management

Building DBMSs out of DBMS parts

Assembling prewritten modules has advantages:

rapid and economical development

technological improvements can quickly beincorporated

proposed new algorithms can first be evaluated

Project GENESIS at the University of Texas

components of DBMS and interfaces among them are

defined new DBMS can be configured within minutes

plug-compatible modules are defined for accessmethods, query optimization, concurrency control,recovery, ...

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Extensible Database Management

Project EXODUS at University of Wisconsin provides certain kernel

facilities including storage manager and type manager

type manager permits definition of hierarchies with multipleinheritance

the storage object is a byte sequence of arbitrary size

buffer management, concurrency control, recovery mechanismsare provided and can be modified

type-independent index structures can be selected

the language E, an C extension, adds the notion of persistentobjects

query processing includes query optimization and evaluation the DBI supplies the description of operators and methods to

implement them

the rule-based optimizer generates C source code

the EXODUS storage manager was used by several vendors (incl.

O2)

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Full-Functionality Approach

Building DBMS with extensive functionality

Providing a wide set of features

Projects PROBE and Starburst active databases

PROBE provides spatial query processing

POSTGRES also combines OO and activedatabase capabilities with the relational model

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Unified Database Management

Example of systems in this category is UniSQL

combines

power and ease of popular development tools

OO development multimedia database integration

organization:

UniSQL/X provides C/S DBMS platform

UniSQL/M allows access to relational and prerelational DBs

UniSQL/4GE Tools for dynamically generating applications

Visual Editor and Media Master allow for viewing and editingof schemas and for sophisticated report generation

the next generation of DBMSs is likely to be patternedafter the UniSQL

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