Foundations of Information Integration Louiqa Raschid Smith School of Business, Department of C.S. and UMIACS Vladimir Zadorozhny UMIACS University of Maryland

Presentation to JRSA - June 15, 1999 Preliminary Observations Information integration is pushing the state-of- the-art of current practice. Roadblocks to success will be inherent to the organization rather than technology limitations.

Presentation to JRSA - June 15, 1999 Dimensions of Interoperability (initial) Platform (machine and O/S) Programming Language Application Semantics Database Model Query Language Database Schema Database Semantics

Presentation to JRSA - June 15, 1999 Technology Solutions and Interoperability Dimensions Middleware Focus on platform, language, application semantics. Database Gateways, MultiDBMS, Heterogeneous DBMS Focus on database integration, database query processing. Data Warehouses Focus on management decision support. Workflow Management NONE OF the solutions address DATABASE SEMANTICS. Additional dimensions: Multi-media (full text, images, video)

Presentation to JRSA - June 15, 1999 Middleware n Middleware allows an application to interoperate with other software. n Eliminates the need to understand and code different implementation details with different levels of implementation transparency.

Presentation to JRSA - June 15, 1999

CORBA approach n PL neutral “contract language” OMG IDL n IDL/PL compiler based on standard Object Request Broker (ORB) architecture ensuring “common address space” and “common data format”. n ORB is a standard middleware that may have specific implementations in different environments n Iona Orbix, BEA ObjectBroker

Presentation to JRSA - June 15, 1999

Transaction processing middleware n Facilitates and makes efficient data requests between application and DBMS u DB system may require an entire OS process per connected user, which is not scalable u Establishing a connection is slow. With many users system performance degrades n IBM CICS, BEA Tuxedo

Presentation to JRSA - June 15, 1999 Database Gateways, Multi-DBMS, Heterogeneous DBMS n Transparent access to multiple physical DBMS n Typically transparent to platform and DBMS product n Provides Logical Database Integration, i.e., transparent support of SQL queries over multiple DBMS n Support joins, unions, views over multiple DBMS n Example products u IBM DataJoiner, u Informix Enterprise Gateway Manager

Presentation to JRSA - June 15, 1999

Enterprise-wide Data Warehouses n Provides uniform access to snapshots of multiple legacy data sources or DBMS. n Create and populate warehouse tables. n Typically does not provide Logical Database Integration, i.e., transparent support of SQL queries over multiple underlying heterogeneous DBMS. n Support for data-marts and datacubes w.r.t. warehouse tables for management decision support. n OLAP (offline decision support) versus OLTP (real- time application).

Presentation to JRSA - June 15, 1999

Workflow Management n Focus on business transactions / event management. n May be transparent to platform and DBMS product. n Typically does not provide Logical Database Integration i.e., transparent support of SQL queries over multiple heterogeneous DBMS. n Example products u Staffware u JetForm

Presentation to JRSA - June 15, 1999 Useful Links n A general product overview site of more then 900 products (formerly DBMS Buyer’s Guide): u n Comprehensive technology guides and articles: u u n A comprehensive guide to Workflow Management: u