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The DB2 Product Family offers open, industrial-strength database management for business
intelligence, transaction processing, and a broad range of applications for all types of businesses.
DB2 server products not only run under mainframe environment, it supports multitude of platforms:
 DB2 for AIX
 DB2 for HP-UX
 DB2 for OS/s
 DB2 for SCO UnixWare
 DB2 for Sun Solaris
 DB2 for Windows NT, Windows 95/98
IBM and Microsoft are working together to provide a wide range of IBM Solutions for Windows NT,
including IBM Suites for Windows NT.
IBM DB2 UDB 5.2 for Windows NT Exploits Windows NT Features:
High availability in the clustered SMP environment is supported by the use of Microsoft Cluster Server
(MSCS) software, which is available in Microsoft Windows NT Server, Enterprise Edition. The MSCS
software provides transparent takeover of the disk and communications resources of a failed node.
Windows applications using Microsoft Transaction Server (MTS) can coordinate distributed, two-phase
commit transactions with multiple DB2 UDB databases.
History of Portable Interfaces
Embedded SQL
In the early days of relational database and throughout the '80s, the only portable interface for applications was
Embedded SQL. There was no common function API and no standard 4GL. Embedded SQL uses a language
specific Precompiler. SQL commands are embedded in a host programming language, such as, C or COBOL. The
Precompile translates the embedded commands into host language statements that use the native API of the
database.
Originally, the defacto standard for Embedded SQL was IBM's DB2 implementation. It served as the basis of the
first ANSI SQL in 1986. Unfortunately, ANSI SQL 86 and its revision in 1989 only defined a subset of Embedded
SQL known as Static SQL. The DB2 implementation of Dynamic SQL continued as the defacto standard well into
the '90s, serving as the basis for implementations like Oracle and FirstSQL.
Open Database API
In the '90s, the SQL Access Group (SAG) was formed for major vendors. SAG defined a portable database API for
SQL. The SAG specification served as the basis of the Microsoft Open Database Connectivity (ODBC)
specification.
What is ODBC?
ODBC is a standardized API (Application Programming Interface). It is a set of function calls based on the SQL
Access Group (SAG) function set for utilizing a SQL database system (back-end system). The SAG set implements
the basic functionality of Dynamic SQL. Embedded SQL commands can be translated to call ODBC.
With ODBC, Microsoft extended the basic SAG function set to include functions for accessing the database catalog
and for controlling and determining the capabilities of ODBC drivers and their data sources (back-ends). They also
have refined and fleshed out the SAG proposal. Microsoft supplies the ODBC Driver Manager for their operating
systems (Windows, Windows 95, Windows NT). The ODBC Driver Manager coordinates access to ODBC drivers
and their associated data sources.
ODBC Architecture
Applications access ODBC functions through the ODBC Driver Manager which dynamically links to the
appropriate ODBC driver. ODBC drivers translate ODBC requests to native format for a specific data source. The
data source may be a complete RDBMS like FirstSQL or it may be a simple file format, like Xbase.
Most ODBC drivers are tied to a single data source. Some, like FirstSQL, support multiple data sources. The
FirstSQL ODBC driver supports both a FirstSQL data source and an Xbase data source.
ODBC Utilization
ODBC provides a robust set of functions for access to a database. The interface is complicated and takes time to
learn to use well.