Re: Weird explain output

From: wd <wd(at)wdicc(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: PostgreSQL General <pgsql-general(at)postgresql(dot)org>
Subject: Re: Weird explain output
Date: 2013-02-04 08:35:51
Message-ID: CABexzmhRDSkGB+4sN+r7fsZHVQ+Otc77ybXy8CocHOJjW6HGnw@mail.gmail.com
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Thanks for your reply.

On Mon, Feb 4, 2013 at 3:48 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> You're worrying about the wrong thing entirely. The right thing to be
> worrying about is why are some of those row estimates off by four orders
> of magnitude, and what you can do to fix that. The planner will never
> deliver sane plans when its estimates are so far off from reality.
>
>
You mean the rows from explain is bigger then the rows real returned?
It caused by a sub query with a filter like ( a and b ) or ( c and d ),
I've tried to create a temp table for it, the explained rows and the real
rows will similarly.

Here is the full output, http://explain.depesz.com/s/M7oo

> From my perspective, you snipped all the interesting parts of this
> output, because the misestimation is evidently happening somewhere down
> in there.
>
> regards, tom lane
>

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