Thread: executebatch:

executebatch:

From

Vladimir Sitnikov

Date:

02 October 2015, 16:29:21

Hi,

I'm observing a performance degradation in executeBatch case when
upgrading 9.3-1102.jdbc41 -> 9.4-1203.

1102 -- 0.78 sec / executeBatch
1203 -- 1.8 sec / executeBatch

It looks like the degradation is caused by the fact that two "flag"
constants share the same value:
QUERY_FORCE_DESCRIBE_PORTAL = 128; and QUERY_DISALLOW_BATCHING = 128;

https://github.com/pgjdbc/pgjdbc/commit/a6bd36faaedc779f932fa76f52bab9550f0fcd6d#diff-54e833c3fd25410b800ff28a1e189227R97

https://github.com/pgjdbc/pgjdbc/commit/a6bd36faaedc779f932fa76f52bab9550f0fcd6d#diff-54e833c3fd25410b800ff28a1e189227R106

Profiling shows that 1203 does QueryExecutorImpl.flushIfDeadlockRisk
-> sendSync a lot.

I wonder if reusing 128 was intentional or not.
I'll try modifying QUERY_FORCE_DESCRIBE_PORTAL=512 to see if that helps.

--
Regards,
Vladimir Sitnikov

Re: executebatch:

From

Craig Ringer

Date:

07 October 2015, 14:43:25

For the record, fixed by Vladimir in
https://github.com/pgjdbc/pgjdbc/pull/380 after comment discussion on

https://github.com/pgjdbc/pgjdbc/commit/a6bd36faaedc779f932fa76f52bab9550f0fcd6d#diff-54e833c3fd25410b800ff28a1e189227R97

On 2 October 2015 at 21:29, Vladimir Sitnikov
<sitnikov.vladimir@gmail.com> wrote:
> Hi,
>
> I'm observing a performance degradation in executeBatch case when
> upgrading 9.3-1102.jdbc41 -> 9.4-1203.
>
> 1102 -- 0.78 sec / executeBatch
> 1203 -- 1.8 sec / executeBatch
>
> It looks like the degradation is caused by the fact that two "flag"
> constants share the same value:
> QUERY_FORCE_DESCRIBE_PORTAL = 128; and QUERY_DISALLOW_BATCHING = 128;
>
https://github.com/pgjdbc/pgjdbc/commit/a6bd36faaedc779f932fa76f52bab9550f0fcd6d#diff-54e833c3fd25410b800ff28a1e189227R97
>
https://github.com/pgjdbc/pgjdbc/commit/a6bd36faaedc779f932fa76f52bab9550f0fcd6d#diff-54e833c3fd25410b800ff28a1e189227R106
>
> Profiling shows that 1203 does QueryExecutorImpl.flushIfDeadlockRisk
> -> sendSync a lot.
>
> I wonder if reusing 128 was intentional or not.
> I'll try modifying QUERY_FORCE_DESCRIBE_PORTAL=512 to see if that helps.
>
> --
> Regards,
> Vladimir Sitnikov
>
>
> --
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--
 Craig Ringer                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services