Re: function calls optimization - Mailing list pgsql-hackers

From Andrzej Barszcz
Subject Re: function calls optimization
Date
Msg-id CAOUVqAzrk2KoWucrKJ5AUest2JdYrvM2qaR93QWB+COAH2EWYg@mail.gmail.com
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In response to Re: function calls optimization  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: function calls optimization  (Andres Freund <andres@anarazel.de>)
List pgsql-hackers
x <> 0 is evaluated first, 1/x only when x <> 0, not ?

czw., 31 paź 2019 o 16:45 Tom Lane <tgl@sss.pgh.pa.us> napisał(a):
Andres Freund <andres@anarazel.de> writes:
> Potentially related note: for nodes like seqscan, combining the qual and projection processing into one expression seems to be a noticable win (at least when taking care do emit two different sets of deform expression steps).

There's just one problem: that violates SQL semantics, and not in
a small way.

        select 1/x from tab where x <> 0

                        regards, tom lane

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