Re: oracle to psql migration - slow query in postgres

On Thu, Oct 14, 2010 at 8:59 PM, Mladen Gogala <mladen(dot)gogala(at)vmsinfo(dot)com>wrote:

> If working with partitioning, be very aware that PostgreSQL optimizer has
> certain problems with partitions, especially with group functions. If you
> want speed, everything must be prefixed with partitioning column: indexes,
> expressions, joins. There is no explicit star schema and creating hash
> indexes will not buy you much, as a matter of fact, Postgres community is
> extremely suspicious of the hash indexes and I don't see them widely used.
> Having said that, I was able to solve the problems with my speed and
> partitioning.
>
>
Could you elaborate on this, please? What do you mean by 'everythin must be
prefixed with partitioning column?'

--sam