Re: Adding nextval() to a select caused hang/very slow execution

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От Eric Raskin
Тема Re: Adding nextval() to a select caused hang/very slow execution
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Msg-id CAF9L-R7ohqis5ZFoTTYQ_23dWkGXY3Phd1-UrZQzUdhx+ZbvDQ@mail.gmail.com
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Ответ на Re: Adding nextval() to a select caused hang/very slow execution  (Tom Lane <tgl@sss.pgh.pa.us>)
Список pgsql-performance
set enable_nestloop=off did the trick.  Execution time when down to seconds per query.

Thanks very much for your help.

On Wed, Nov 4, 2020 at 4:16 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
Eric Raskin <eraskin@paslists.com> writes:
> So, things get even weirder.   When I execute each individual select
> statement I am generating from a psql prompt, they all finish very
> quickly.
> If I execute them inside a pl/pgsql block, the second one hangs.
> Is there something about execution inside a pl/pgsql block that is
> different from the psql command line?

Generic vs specific plan, perhaps?  Are you passing any parameter
values in from plpgql variables?

IIRC, you could force the matter by using EXECUTE, though it's
somewhat more notationally tedious.  In late-model PG versions,
plan_cache_mode could help you too.

                        regards, tom lane
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