Message-ID: <fbfaf1a0a5a83d35971b7d77c5cbf64d72375dc4.camel@cybertec.at>
Subject: Re: Performance down with JDBC 42
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: "Abraham, Danny" <danny_abraham@bmc.com>, psql-performance
	 <pgsql-performance@postgresql.org>
Date: Sat, 04 Nov 2023 22:07:19 +0100
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On Sat, 2023-11-04 at 19:08 +0000, Abraham, Danny wrote:
> Asking for help with a JDBC related issue.
> Environment: Linux 7.9 PG 14.9 , very busy PG Server.
>=20
> A big query - 3 unions and about 10 joins runs :
> - 70ms on psql , DBeaver with JDBC 42  and  in our Server using old JDBC =
9.2
> - 2500 ms in our Server using new JDBC 42 driver. ( and  this is running =
many times)=20
>=20
> Question: Is there a structured way to identify optimization setup ( Plan=
ner Method s ) changes?
> Are there any known changes specific to JDBC 42.=20

What I would do is enable auto_explain and look at the execution plan
when the statement is run by the JDBC driver.  Then you can compare the
execution plans and spot the difference.

Yours,
Laurenz Albe