Re: Measuring the Query Optimizer Effect: Turning off the QO?

From: Andrew Gierth <andrew(at)tao11(dot)riddles(dot)org(dot)uk>
To: Tom Mercha <mercha_t(at)hotmail(dot)com>
Cc: "pgsql-general\(at)lists(dot)postgresql(dot)org" <pgsql-general(at)lists(dot)postgresql(dot)org>
Subject: Re: Measuring the Query Optimizer Effect: Turning off the QO?
Date: 2019-07-08 14:23:34
Message-ID: 875zoc7h29.fsf@news-spur.riddles.org.uk
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>>>>> "Tom" == Tom Mercha <mercha_t(at)hotmail(dot)com> writes:

Tom> Hi All

Tom> As we know, a query goes through number of stages before it is
Tom> executed. One of these stages is query optimization (QO).

That's not really true at all. One of the stages is query _planning_,
which takes the (rewritten) query as input and converts it to something
that the executor can take action on. There isn't actually any separate
"optimization" phase.

--
Andrew (irc:RhodiumToad)

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