In 1993, pundits in the computer industry predicted the imminent demise of the mainframe. The computing infrastructure of the future, they pronounced, would be a highly distributed and loosely connected collection of personal computers and client-server systems.
IBM was all but written off as a relevant player in the industry.
As IBM tried to re-invent itself through the following ways:
- IBM reduced mainframe prices
- Started giving support to distributed client-server Windows,Linux,Unix
- Earlier DB2 was Mainframe database. Now it is changed to available to Windows, UNIX and Linux
- IBM introduced DB2 connect
DB2 Connect:Many people have misunderstanding that DB2 connect only connects distributed applications(DA) to DB2. But this is wrong.
DB2 Connect’s purpose in life is to connect applications to data, not one database to another database
DB2 Connect simply delivers the SQL from the application to the DB2 database for processing. It does not rewrite it or alter it in any way
What is an application?
we can say an application means code which issues SQl queries.
It allows access to DB2 servers running under the control of OS/390®, z/OS, i5/OS™, OS/400®, VSE and VM from computer code that is running on other platforms (Linux, UNIX, and Windows).
While DB2 Connect can connect to database servers on all of these platforms, we will be talking mostly about connecting applications to DB2 running under control of z/OS.
DB2 Connect implements this intuitively simple access methodology in one of three different mechanisms:
- Federated databases
- Stored procedures
- SQL functions