From: Tom Lane <tgl@sss.pgh.pa.us>
To: Mladen Gogala <gogala.mladen@gmail.com>
cc: pgsql-performance@lists.postgresql.org
Subject: Re: Big Performance drop of Exceptions in UDFs between V11.2 and 13.4
In-reply-to: <01186dcc-bf1e-0c25-b6e6-9a1c6b52d226@gmail.com>
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 <01186dcc-bf1e-0c25-b6e6-9a1c6b52d226@gmail.com>
Comments: In-reply-to Mladen Gogala <gogala.mladen@gmail.com>
	message dated "Sat, 21 Aug 2021 11:29:44 -0400"
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Date: Sat, 21 Aug 2021 14:04:49 -0400
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Mladen Gogala <gogala.mladen@gmail.com> writes:
> I know that 14 is a beta version but the performance is significantly 
> worse than v13 (I assume it's 13.4). Head revision is better than v14 
> but still worse than v13.  Can you expand a bit on the difference?

[ shrug... ]  I don't see any meaningful differences between those
numbers --- they're within 3% or so across versions, which is less
than the margin of error considering I wasn't trying to control
for outside effects like CPU speed stepping.  Microbenchmarks like
this one are notoriously noisy.  Maybe there's some real difference
there, but these numbers aren't to be trusted that much.

What I was looking for was some evidence matching Laurent's report of
the exception-recovery path being 500X slower than non-exception.
That would have been obvious even with the sloppiest of measurements
... but I'm not seeing it.

			regards, tom lane