On Dec 19, 2007, at 6:39 PM, Tom Lane wrote:
The thing that concerns me is dead tuples on the table_stats table. Ibelieve that every insert of new data in one of the monitored tables will result in an UPDATE of the table_stats table. When thousands ( or millions ) of rows are inserted, the select performance ( even trying with an index ) on table_stats slows down in a hurry.Yup. FWIW, 8.3's "HOT" tuple updates might help this quite a lot. Not a lot to be done about it in 8.0.x though :-(
A work-around others have used is to have the trigger just insert into a 'staging' table and then periodically take the records from that table and summarize them somewhere else. You still have a vacuum concern on the staging table, but the advantage is that you trigger path is a simple insert instead of an update, which is effectively a delete and an insert.
This is a case where a cron'd vacuum that runs once a minute is probably a wise idea.
-- Decibel!, aka Jim C. Nasby, Database Architect decibel@xxxxxxxxxxx Give your computer some brain candy! www.distributed.net Team #1828
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