Re: COPY FROM WHEN condition

Hi,

On January 29, 2019 6:25:59 AM PST, Tomas Vondra <tomas.vondra@2ndquadrant.com> wrote:
>On 1/29/19 8:18 AM, David Rowley wrote:
>> ...
>> Here are my performance tests of with and without your change to the
>> memory contexts (I missed where you posted your results).
>> 
>> $ cat bench.pl
>> for (my $i=0; $i < 8912891; $i++) {
>> print "1\n1\n2\n2\n";
>> }
>> 36a1281f86c: (with your change)
>> 
>> postgres=# copy listp from program $$perl ~/bench.pl$$ delimiter '|';
>> COPY 35651564
>> Time: 26825.142 ms (00:26.825)
>> Time: 27202.117 ms (00:27.202)
>> Time: 26266.705 ms (00:26.267)
>> 
>> 4be058fe9ec: (before your change)
>> 
>> postgres=# copy listp from program $$perl ~/bench.pl$$ delimiter '|';
>> COPY 35651564
>> Time: 25645.460 ms (00:25.645)
>> Time: 25698.193 ms (00:25.698)
>> Time: 25737.251 ms (00:25.737)
>> 
>
>How do I reproduce this? I don't see this test in the thread you
>linked,
>so I'm not sure how many partitions you were using, what's the
>structure
>of the table etc.

I think I might have a patch addressing the problem incidentally. For pluggable storage I slotified copy.c, which also removes the first heap_form_tuple. Quite possible that nothing more is needed. I've removed the batch context altogether in yesterday's rebase, there was no need anymore.

Andres
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