Re: [BUGS] BUG #2737: hash indexing large table fails,while btree of same index works - Mailing list pgsql-performance

From Simon Riggs
Subject Re: [BUGS] BUG #2737: hash indexing large table fails,while btree of same index works
Date
Msg-id 1163233075.3634.944.camel@silverbirch.site
Whole thread Raw
In response to Re: [BUGS] BUG #2737: hash indexing large table fails, while btree of same index works  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: [BUGS] BUG #2737: hash indexing large table fails,while btree of same index works  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-performance
On Fri, 2006-11-10 at 18:55 -0500, Tom Lane wrote:
> [ cc'ing to pgsql-performance because of performance issue for hash indexes ]
>
> "Balazs Nagy" <bnagy@thenewpush.com> writes:
> > Database table size: ~60 million rows
> > Field to index: varchar 127
>
> > CREATE INDEX ... USING hash ...

I'd be interested in a performance test that shows this is the best way
to index a table though, especially for such a large column. No wonder
there is an 8GB index.

> One thought that comes to mind is to require hash to do an smgrextend()
> addressing the last block it intends to use whenever it allocates a new
> batch of blocks, whereupon md.c could adopt a saner API: allow
> smgrextend but not other calls to address blocks beyond the current EOF.

> Thoughts?

Yes, do it.

--
  Simon Riggs
  EnterpriseDB   http://www.enterprisedb.com



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