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Re: Bad plan when join on function - Mailing list pgsql-performance

From Tom Lane
Subject Re: Bad plan when join on function
Date
Msg-id 21547.1295300024@sss.pgh.pa.us
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In response to Re: Bad plan when join on function  (Pavel Stehule <pavel.stehule@gmail.com>)
Responses Re: Bad plan when join on function
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Pavel Stehule <pavel.stehule@gmail.com> writes:
> it should to work without functional index - but not sure about effectivity

As long as the function is VOLATILE, the planner can't use any
intelligent query plan.  Merge or hash join both require at least
stable join keys.

            regards, tom lane

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