Re: Weird function behavior from Sept 11 snapshot - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Weird function behavior from Sept 11 snapshot
Date
Msg-id 14096.968776744@sss.pgh.pa.us
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In response to Re: Weird function behavior from Sept 11 snapshot  (Thomas Lockhart <lockhart@alumni.caltech.edu>)
List pgsql-hackers
Thomas Lockhart <lockhart@alumni.caltech.edu> writes:
> Another followup: on 7.0.2, with different optimizations etc,
> sum(float8) takes 1.95 seconds, rather than the 5.2 on the current tree.
> I'd better look at the compilation optimizations; is there another
> explanation for the factor of 2.6 difference (!!)?

If you are running with --enable-cassert then there is a whole bunch
of memory-stomp debugging overhead turned on in current sources,
including such time-consuming stuff as clearing every pfree'd block.
7.0.*'s --enable-cassert is not nearly as expensive.

I plan to make that stuff not-default when we go beta, but right now
it seems like a good idea to have it on for testing...
        regards, tom lane


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