Re: PG for DataWarehouse type Queries

On 8/3/07, Ow Mun Heng <Ow(dot)Mun(dot)Heng(at)wdc(dot)com> wrote:
> Can anyone shed some light on this. I just would like to know if queries
> for raw data (not aggregregates) is expected to take a long time.
> Running times between 30 - 2 hours for large dataset pulls.
>
> Involves lots of joins on very large tables (min 1 millon rows each
> table, 300 columns per table)
>
> Joins are done in the form of Left joins (sometimes on the same tables,
> due to normalisation)
>
> Is 30min - 2hours too long or is this considered "normal"??

That depends entirely on your query, your dataset, the machine you're
using, etc. Your best bet is probably to post an EXPLAIN ANALYZE of
your query along with some description of what's going on and what
you're running this all on (pg version, machine specs, etc.) and see
if someone can come up with an acceptable way to make the query
faster.

- Josh