>
> I have performance problems with a huge database
> (there a 2 tables with 40 millions of records) and
> many users doing updates and queries on it. I 've
> perform severals VACUMM on the database with poor
> results.
> Each table have an unique index and I added other
> indexes to improve the performance. But when there are
> inserts (not too many) the performance fall.
> What can I do to improve the performace? I hear any
> opinion.
>
Bear in mind, every index has to be updated when records
are inserted. An unique one makes it even worse, because
a search for duplicates must be performed.
You may give the idea some thought, if this index really
has to be unique. I sometimes use a 'timestamp-insert'
column to allow duplicates and retrieve unique entries by
a SELECT DISTINCT ON construct.
Regards, Christoph