Re: text search: tablescan cost for a tsvector

From: Robert Haas <robertmhaas(at)gmail(dot)com>
To: Marc Mamin <M(dot)Mamin(at)intershop(dot)de>
Cc: pgsql-performance(at)postgresql(dot)org, oleg(at)sai(dot)msu(dot)su
Subject: Re: text search: tablescan cost for a tsvector
Date: 2012-02-29 18:32:48
Message-ID: CA+TgmoZgQBeu2KN305hwDS+aXW7YP0YN9vZwBsbWA8Unst+cew@mail.gmail.com
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On Mon, Feb 6, 2012 at 6:05 AM, Marc Mamin <M(dot)Mamin(at)intershop(dot)de> wrote:
> without analyze: http://explain.depesz.com/s/6At
> with analyze:    http://explain.depesz.com/s/r3B

I think this is the same issue complained about here:

http://archives.postgresql.org/message-id/4ED68EEC.9030906@krogh.cc

And here:

http://archives.postgresql.org/message-id/CANxtv6XiuiqEkXRJU2vk=xKAFXrLeP7uVhgR-XMCyjgQz29EFQ@mail.gmail.com

The problem seems to be that the cost estimator doesn't know that
detoasting is expensive.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

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