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List:       postgresql-general
Subject:    Re: Performance Issue after upgrade from 9 to 11
From:       Tom Lane <tgl () sss ! pgh ! pa ! us>
Date:       2020-01-29 23:54:12
Message-ID: 4057.1580342052 () sss ! pgh ! pa ! us
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Perumal Raj <perucinci@gmail.com> writes:
> I have used pg_upgrade which runs "analyze_new_cluster.sh" as post upgrade
> activity across all DB on cluster.

pg_upgrade itself won't run that script, it only creates it for you
to run.

> Also, I have executed manual vacuum on all individual tables. However the
> behavior is same until i disable the above said parameter.

Did those manual vacuums include an "analyze" option?

If you in fact haven't got analyze results on your tables, that might
explain your problems.  autovacuum would eventually rectify the situation
for larger tables, but it might never get around to small seldom-updated
tables.

If that's not it, I again direct your attention to the
Slow_Query_Questions wiki page.  That summarizes a lot of past experience
with solving performance problems, and you're not endearing yourself to
potential helpers by refusing to follow the process.

			regards, tom lane


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