Re: BUG #10194: Stable function in select clause cann't be optimized to one call?

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От Tom Lane
Тема Re: BUG #10194: Stable function in select clause cann't be optimized to one call?
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Msg-id 4618.1398973036@sss.pgh.pa.us
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Ответ на BUG #10194: Stable function in select clause cann't be optimized to one call?  (digoal@126.com)
Ответы Re: BUG #10194: Stable function in select clause cann't be optimized to one call?
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digoal@126.com writes:
> Why stable function in select clause cann't optimized to one time call?

Because its value might change between planning and execution.

There was some discussion awhile back of performing run-time caching of
the result, but it isn't done yet, and would impose some costs of its own.

BTW, this sort of question is not a bug.

            regards, tom lane

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