Re: Shouldn't we have a way to avoid "risky" plans? - Mailing list pgsql-performance

From Claudio Freire
Subject Re: Shouldn't we have a way to avoid "risky" plans?
Date
Msg-id AANLkTimD174+muSzfg4FGfat26V2ebEsDw7f9sLcwBR7@mail.gmail.com
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In response to Re: Shouldn't we have a way to avoid "risky" plans?  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Shouldn't we have a way to avoid "risky" plans?
List pgsql-performance
On Wed, Mar 23, 2011 at 6:00 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Claudio Freire <klaussfreire@gmail.com> writes:
>> In my head, safer = better worst-case performance.
>
> If the planner starts operating on the basis of worst case rather than
> expected-case performance, the complaints will be far more numerous than
> they are today.

I imagine, that's why, if you put my comment in context, I was talking
about picking a safer plan only when the "better on average one" fails
miserably.

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