200 million rows is a lot. You need to check the
limit for a single table in DB2 which depends on
the configured pagesize and ranges from 64 GB
to 512 GB for single-partition-tables (no EEE).

You might consider partitioning your database across
several partitions using DB2 EEE or in DB2 ESE (Version 8.1),
this might improve performance, because the delete will
run in parallel mode.

From my point of view you need some kind of fragmentation
technology like the one Informix offers.
With Informix you can fragment your table using for example
range fragmentation into several dbspaces. This allows you
to detach a single fragment without any resource consuming
delete process, it takes only a second and your data is
"deleted".

But this is not possible with DB2 (at least not yet, but the
IFMX guys will work on a future DB2 version, hopefully).
You might consider using several stand-alone-tables and
combining them thru a union-view.
I read something that in Version 8.1 also inserts/updates/deletes
against union views are possible. So that might help.


Best regards

Eric
--
IT-Consulting Herber
WWW: http://www.herber-consulting.de
Email: eric@herber-consulting.de

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