On 11/8/22 18:06, Wells Oliver wrote:
Upgraded 13.7 to 14.4 on RDS by restoring from a snapshot and upgrading that.
Off-topic, but did you rebuild all indices with text columns? That might
not be relevant in RDS (who knows exactly what's underneath the hood?) but
it might be.
My configuration files and instance type are exactly the same. After
upgrading, I ran vacuumdb -Z -j 8 and that did its thing.
The upgraded database is slower. I'm running EXPLAIN ANALYZE for various
queries and it's getting to the same plan, but it's taking longer to execute.
I've always felt after major upgrades there's some element to "priming the
database" where it seems to be much faster a few days in after broader
usage. I realize it sounds absurd but I'll swear by this being my
experience. So I'm willing to think to some degree that queries will
execute faster the more people use the upgraded database.
Just wondering if there is anything I might specifically look at that
would account for some of the slowness.
https://dba.stackexchange.com/a/295145/63913
That answer is about loading the cache yourself, either the old school
SELECT * FROM foo WHERE ... method, or using using the pg_prewarm extension.
--
Angular momentum makes the world go 'round.
