| From: | "Jim C(dot) Nasby" <jnasby(at)pervasive(dot)com> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | Scott Marlowe <smarlowe(at)g2switchworks(dot)com>, RAJU kumar <raju_19db(at)rediffmail(dot)com>, pgsql-admin(at)postgresql(dot)org |
| Subject: | Re: Hash index |
| Date: | 2005-08-30 20:17:38 |
| Message-ID: | 20050830201738.GD77007@pervasive.com |
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| Lists: | pgsql-admin |
On Tue, Aug 30, 2005 at 03:32:26PM -0400, Tom Lane wrote:
> That leaves hash. I'm hoping someone will step up and do WAL logging
> for hash in the near future. Unlike rtree, I'm not expecting that we
> might get rid of hash indexes. Even if the performance problems never
> get fixed, we use hash index opclasses to manage datatype-specific
> hashing for hash joins, hash aggregation, etc, so if we removed hash
> indexes we'd need to find some other representation for all that.
So does that mean a hash index could (theoretically) improve the
performance of a hash join or hash aggregation?
--
Jim C. Nasby, Sr. Engineering Consultant jnasby(at)pervasive(dot)com
Pervasive Software http://pervasive.com 512-569-9461
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