triggers, sequence - need advice

From: Norman Dunbar <Norman.Dunbar_at_lfs.co.uk>
Date: Fri, 1 Aug 2003 10:14:27 +0100
Message-ID: <E2F6A70FE45242488C865C3BC1245DA703FAAFE7@lnewton.leeds.lfs.co.uk>

Morning,

Pin the triggers - they get loaded each time they are fired.

Are the sequence values being used to index any tables - this will affect performance as the new entries all hit the same block in the index. If there are many inserts to these tables then you'll suffer !

The solution is to create a reverse index rather than a normal one - this will then affect the clustering factor but will spread the load over all the index blocks rather than just the newest one. In addition, it will allow the index entries freed up by deleted rows to be re-used (eventually) which is not the case when indexing on a sequence number which is always increasing.

Cheers,
Norm.

Norman Dunbar
Database/Unix administrator
Lynx Financial Systems Ltd.
mailto:Norman.Dunbar_at_LFS.co.uk

Tel: 0113 289 6265
Fax: 0113 289 3146
URL: http://www.Lynx-FS.com


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Received on Fri Aug 01 2003 - 04:14:27 CDT