> I'm not an SQL or PostgreSQL expert.
>
> I'm getting abysmal performance on a nested query and
> need some help on finding ways to improve the performance:
[snip]
> select * from attributes_table where id in (select id from
> attributes where (name='obsid') and (value='oid00066'));
This is the classic IN problem (much improved in 7.4 dev I believe). The
recommended approach is to rewrite the query as an EXISTS form if
possible. See the mailing list archives for plenty of examples.
Could you not rewrite this as a simple join though?
- Richard