Re: Most efficient large update?

broom_at_voicenet.com (broom) wrote in message news:<c948eb61.0105270642.310ed246_at_posting.google.com>...
> "Daniel A. Morgan" <dmorgan_at_exesolutions.com> wrote in message news:<3B106A54.64822210_at_exesolutions.com>...
> > You try to update 100,000 records in one shot and you will likely not
> > succeed due to rollback segment space.
>
> Actually, no. I can throw 50GB at single use RBS if I need it.
> I'm aware of the issues concerning rbs activity. The key issue is the
> amount of time related the updates. Any hints in that direction?

The only additional suggestion I can give is to run several updates in parallel, each session responsible for one data range. In order to make this work perfectly, you have to make sure the ranges won't overlap on Oracle blocks. That's not trivial because you can't assume that session 1 updates rows beginning with 'A' to 'M', session 2 updates 'N' to 'Z' and they won't overlap on blocks. Block overlap causes serious undo activity. So roughly estimate how far apart the two ranges should stay away from each other.

Yong Huang
yong321_at_yahoo.com Received on Sun May 27 2001 - 23:02:13 CDT