Re: Measuring the Query Optimizer Effect: Turning off the QO? - Mailing list pgsql-general

From Andrew Gierth
Subject Re: Measuring the Query Optimizer Effect: Turning off the QO?
Date
Msg-id 875zoc7h29.fsf@news-spur.riddles.org.uk
Whole thread Raw
In response to Measuring the Query Optimizer Effect: Turning off the QO?  (Tom Mercha <mercha_t@hotmail.com>)
Responses Re: Measuring the Query Optimizer Effect: Turning off the QO?  (Tom Mercha <mercha_t@hotmail.com>)
List pgsql-general
>>>>> "Tom" == Tom Mercha <mercha_t@hotmail.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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