Re: Clustered/covering indexes (or lack thereof :-)

adrobj wrote:
> This is probably a FAQ, but I can't find a good answer...
>
> So - are there common techniques to compensate for the lack of
> clustered/covering indexes in PostgreSQL? To be more specific - here is my
> table (simplified):
>
> topic_id int
> post_id int
> post_text varchar(1024)
>
> The most used query is: SELECT post_id, post_text FROM Posts WHERE
> topic_id=XXX. Normally I would have created a clustered index on topic_id,
> and the whole query would take ~1 disk seek.
>
> What would be the common way to handle this in PostgreSQL, provided that I
> can't afford 1 disk seek per record returned?

You can cluster the table, see
http://www.postgresql.org/docs/8.2/interactive/sql-cluster.html.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com