Re: Performance issue

In response to Willo van der Merwe <willo(at)mirasol(dot)co(dot)za>:

> Hi Guys,
>
> I have something odd. I have Gallery2 running on PostgreSQL 8.1, and
> recently I upgraded to 8.1.9-1.el4s1.1 (64bit). The issue here really is
> how do I get PostgreSQL to work with their horrible code. The queries
> they generate look something like :
> SELECT blah, blah FROM table1, table2 WHERE <some relational stuff> AND
> id IN (<here a list of 42000+ IDs are listed>)
>
> On the previous version (which I can't recall what it was, but it was a
> version 8.1) the queries executed fine, but suddenly now, these queries
> are taking up-to 4 minutes to complete. I am convinced it's the
> parsing/handling of the IN clause. It could, of course, be that the list
> has grown so large that it can't fit into a buffer anymore. For obvious
> reasons I can't run an EXPLAIN ANALYZE from a prompt.

Those reasons are not obvious to me. The explain analyze output is
going to be key to working this out -- unless it's something like
your postgresql.conf isn't properly tuned.

> I vacuum and
> reindex the database daily.
>
> I'd prefer not to have to rewrite the code, so any suggestions would be
> very welcome.

--
Bill Moran
Collaborative Fusion Inc.
http://people.collaborativefusion.com/~wmoran/

wmoran(at)collaborativefusion(dot)com
Phone: 412-422-3463x4023