Re: Performance weirdness with/without vacuum analyze

Harry,

>    It has been suggested to me that I resubmit this question to this list,
> rather than the GENERAL list it was originaly sent to.
>
>    I asked earlier about ways of doing an UPDATE involving a left outer
> join and got some very useful feedback.

The query you posted will always be somewhat slow due to the forced join
order, which is unavodable with a left outer join.

However, regarding your peculiar behaviour, please post:

1) Your random_page_cost and effective_cache_size settings
2) The EXPLAIN ANALYZE of each query instead of just the EXPLAIN

Thanks!

--
Josh Berkus
Aglio Database Solutions
San Francisco