Re: More stable query plans via more predictable column statistics - Mailing list pgsql-hackers

From Tom Lane
Subject Re: More stable query plans via more predictable column statistics
Date
Msg-id 26465.1457540894@sss.pgh.pa.us
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In response to Re: More stable query plans via more predictable column statistics  ("Shulgin, Oleksandr" <oleksandr.shulgin@zalando.de>)
Responses Re: More stable query plans via more predictable column statistics
List pgsql-hackers
"Shulgin, Oleksandr" <oleksandr.shulgin@zalando.de> writes:
> Yes, I now recall that my actual concern was that sample_cnt may calculate
> to 0 due to the latest condition above, but that also implies track_cnt ==
> 0, and then we have a for loop there which will not run at all due to this,
> so I figured we can avoid calculating avgcount and running the loop
> altogether with that check.  I'm not opposed to changing the condition if
> that makes the code easier to understand (or dropping it altogether if
> calculating 0/0 is believed to be harmless anyway).

Avoiding intentional zero divides is good.  It might happen to work
conveniently on your machine, but I wouldn't think it's portable.
        regards, tom lane



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