Re: Slow query after upgrades - Mailing list pgsql-jdbc

From Oliver Jowett
Subject Re: Slow query after upgrades
Date
Msg-id 4761A221.80604@opencloud.com
Whole thread Raw
In response to Slow query after upgrades  (Tom Duffey <tduffey@techbydesign.com>)
Responses Re: Slow query after upgrades  (Tom Duffey <tduffey@techbydesign.com>)
List pgsql-jdbc
Tom Duffey wrote:

> I'm leaving the old JDBC driver there for now but am wondering if anyone
> has any ideas what I should look for to find a solution to this?  I
> jProfiled the execution and it is indeed the JDBC query that is taking
> significantly more time to execute with the newer driver in place.

Identify the slow query and build a testcase for that particular query
and send it to the list?

Also, beware of counting blocking I/O time as CPU time when doing Java
profiling. Probably, the Java side is just blocking waiting on the server.

There are server-side logging options you might want to look at too.

The most likely cause is that more recent drivers ("recent" is very
relative here, I think it went in for the 8.0 driver?) use the extended
query protocol which can result in different plans for some queries.

-O

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