From: Divakar Singh <dpsmails@yahoo.com>
To: Cédric Villemain <cedric.villemain.debian@gmail.com>
To: depesz@depesz.com
Cc: pgsql-performance@postgresql.org
Subject: Re: Insert performance with composite index
Date: Tue, 2 Nov 2010 05:51:07 -0700 (PDT)
Message-ID: <577700.37613.qm@web65406.mail.ac4.yahoo.com> (raw)
In-Reply-To: <AANLkTi=FpwtFLp07ZP36DzLFhpE0xdmQW6O=_rEyM5ov@mail.gmail.com>
References: <293254.80548.qm@web65413.mail.ac4.yahoo.com>
<AANLkTi=CSjxW9K67EP0SVu-_J1YM4eSPkHaziC_88YTP@mail.gmail.com>
<20101102094539.GA6686@depesz.com>
<AANLkTi=FpwtFLp07ZP36DzLFhpE0xdmQW6O=_rEyM5ov@mail.gmail.com>
May be a query that is filtering based on these 2 columns?
Best Regards,
Divakar
________________________________
From: Cédric Villemain <cedric.villemain.debian@gmail.com>
To: depesz@depesz.com
Cc: Divakar Singh <dpsmails@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 <depesz@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: depesz@depesz.com / aim:depeszhdl / skype:depesz_hdl / gg:6749007
>
--
Cédric Villemain 2ndQuadrant
http://2ndQuadrant.fr/ PostgreSQL : Expertise, Formation et Support
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To: pgsql-performance@postgresql.org
Cc: dpsmails@yahoo.com, cedric.villemain.debian@gmail.com, depesz@depesz.com
Subject: Re: Insert performance with composite index
In-Reply-To: <577700.37613.qm@web65406.mail.ac4.yahoo.com>
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