Re: A pessimistic planner

From: Tom Lane
Subject: Re: A pessimistic planner
Date: ,
Msg-id: 21114.1416546725@sss.pgh.pa.us
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In response to: A pessimistic planner  (Stuart Bishop)
List: pgsql-performance

Stuart Bishop <> writes:
> I was wondering if the planner should be much more pessimistic,
> trusting in Murphy's Law and assuming the worst case is the likely
> case? Would this give me a much more consistent system?

Well, it would give uniformly awful plans for cases where fast-start
plans are actually useful ... and there are plenty.

We do need to think of ways to account for risk, but I don't think
that jamming the tiller all the way over is likely to be a net
improvement.

            regards, tom lane



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