multi column query

From: "Sriram Dandapani" <sdandapani(at)counterpane(dot)com>
To: <pgsql-performance(at)postgresql(dot)org>
Subject: multi column query
Date: 2006-04-13 00:32:32
Message-ID: 6992E470F12A444BB787B5C937B9D4DF03EF488C@ca-mail1.cis.local
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

Hi

When I update a table that has 20 columns and the where clause includes
16 of the columns (this is a data warehousing type update on aggregate
fields),

The bitmap scan is not used by the optimizer. The table is indexed on 3
of the 20 fields. The update takes really long to finish (on a 6 million
row table)

Do I need to do some "magic" with configuration to turn on bitmap scans.

Responses

Browse pgsql-performance by date

  From Date Subject
Next Message Tom Lane 2006-04-13 00:35:14 Re: pgmemcache
Previous Message Jim C. Nasby 2006-04-13 00:10:25 Re: pgmemcache