Re: partitioned table and ORDER BY indexed_field DESCLIMIT 1 - Mailing list pgsql-performance

From Simon Riggs
Subject Re: partitioned table and ORDER BY indexed_field DESCLIMIT 1
Date
Msg-id 1193562833.4242.670.camel@ebony.site
Whole thread Raw
In response to Re: partitioned table and ORDER BY indexed_field DESCLIMIT 1  ("Luke Lonergan" <LLonergan@greenplum.com>)
Responses Re: partitioned table and ORDER BY indexed_field DESCLIMIT 1
List pgsql-performance
On Sat, 2007-10-27 at 17:48 -0400, Luke Lonergan wrote:
> Works great - plans no longer sort, but rather use indices as
> expected.  It's in use in Greenplum now.
>
> It's a simple approach, should easily extend from gpdb to postgres.
> The patch is against gpdb so someone needs to 'port' it.

The part of the patch that didn't work for me was the nrels==1 bit. The
way it currently works there is only ever 0 or 2+ rels. The normal
Postgres code has to cater for the possibility of a non-empty parent
table, which seems to destroy the possibility of using this technique.

I agree its annoying and I have a way of doing this, but that's an 8.4
thing now.

Anybody think different?

--
  Simon Riggs
  2ndQuadrant  http://www.2ndQuadrant.com


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