Обсуждение: Re: Postgres: Queries are too slow after upgrading to PG17 from PG15

Sajith Prabhakar Shetty <ssajith@blackduck.com> writes:
> Now surprisingly one of the query i took from application which used to execute in 2s in PG15, is now taking 1min+ in
PG17.

The data you've actually showed us does not back up that complaint.
But I do see a 2x slowdown.

> Explain plan of the two queries almost same, all the joins and paths used are exactly same.

Yeah, that is odd.  The only simple explanation I can think of is that you
are using a debug build of v17.

            regards, tom lane

Sajith Prabhakar Shetty <ssajith@blackduck.com> writes:
> In my first test, I used pg_upgrade to upgrade the instance from 15 to 17, and in my second test, I created PG15 and
PG17separately from brew repo, I don’t think I am using debug build here. 

Might be worth checking the brew recipes... it's common for packagers to
set the debug option for beta versions, and I could believe that whoever
packages PG for HomeBrew forgot to take that out again for 17.0.

But, assuming it's not that, could you put together a self-contained
test case that demos what you're seeing?

            regards, tom lane