RE: pg_stat_statements: duplicated external query texts with MSY2

>Julien Rouhaud <rjuju123(at)gmail(dot)com> writes:
>> On Mon, Jun 8, 2020 at 11:28 PM legrand legrand
>> <legrand_legrand(at)hotmail(dot)com> wrote:
>>> pgbench -i postgres
>>> pgbench -c20 -t5 postgres
>>> generates the attached pgss_query_texts.stat,
>>> where "BEGIN" and "UPDATE pgbench_accounts SET abalance = abalance + $1 WHERE aid = $2"
>>> appears 20 times ...

>> Is the duplication only in the query text file? Looking at the code
>> the query text part is stored holding a shared lwlock, so it seems
>> like an expected behavior (less overhead but might store duplicated
>> query text)

> I agree, this looks like operating-as-designed: different processes can
> store the same query text and only later discover that they were creating
> duplicate hash table entries. It's a bit surprising that the duplication
> would be reproducible, but it just depends on timing. Maybe this is
> telling us something about how scheduling works under MSYS2.
>
> regards, tom lane

Hello,

duplication is only in the query text file, selecting plans or calls in the view
pg_stat_statements are corrects.

For information, this is reproducable with official build
"PostgreSQL 12.1, compiled by Visual C++ build 1914, 64-bit"
on windows 10.

Regards
PAscal