May be a query that is filtering based on these 2 columns? Best Regards, Divakar
________________________________ From: Cédric Villemain <cedric.villemain.deb...@gmail.com> To: dep...@depesz.com Cc: Divakar Singh <dpsma...@yahoo.com>; pgsql-performance@postgresql.org Sent: Tue, November 2, 2010 4:34:42 PM Subject: Re: [PERFORM] Insert performance with composite index 2010/11/2 hubert depesz lubaczewski <dep...@depesz.com>: > On Mon, Nov 01, 2010 at 02:57:56PM +0100, Cédric Villemain wrote: >> > CONSTRAINT tableindex_pkey PRIMARY KEY (tableindex) >> > ) >> > the index definition is >> > CREATE INDEX "PK_AT2" >> > ON ABC >> > USING btree >> > (event, tableindex) >> > TABLESPACE sample; >> >> Indexing twice the same column is useless. (perhaps move your PK to >> the tablespace 'sample' is good too ?) > > why do you say that? > these are not the same indexes and they serve different purposes. Given that tableindex is the PK column, I really like to now the usage pattern for having it indexed twice. > > Best regards, > > depesz > > -- > Linkedin: http://www.linkedin.com/in/depesz / blog: http://www.depesz.com/ > jid/gtalk: dep...@depesz.com / aim:depeszhdl / skype:depesz_hdl / gg:6749007 > -- Cédric Villemain 2ndQuadrant http://2ndQuadrant.fr/ PostgreSQL : Expertise, Formation et Support -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
