Re: constant vs function param differs in performance

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От Tom Lane
Тема Re: constant vs function param differs in performance
Дата
Msg-id 5187.1068843554@sss.pgh.pa.us
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Ответ на constant vs function param differs in performance  ("SZŰCS Gábor" <surrano@mailbox.hu>)
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"=?iso-8859-2?B?U1rbQ1MgR+Fib3I=?=" <surrano@mailbox.hu> writes:
> I have two SQL function that produce different times and I can't understand
> why.

The planner often produces different plans when there are constants in
WHERE clauses than when there are variables, because it can get more
accurate ideas of how many rows will be retrieved.

            regards, tom lane

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