Re: BUG: endless lseek(.., SEEK_END) from select queries on x64 builds - Mailing list pgsql-performance

From Stephen Frost
Subject Re: BUG: endless lseek(.., SEEK_END) from select queries on x64 builds
Date
Msg-id 20130222133723.GR16142@tamriel.snowman.net
Whole thread Raw
In response to BUG: endless lseek(.., SEEK_END) from select queries on x64 builds  (Markus Schulz <msc@antzsystem.de>)
List pgsql-performance
Markus,

* Markus Schulz (msc@antzsystem.de) wrote:
> as you can see the query runs fine.
> I can run this query from a bash-psql-while-loop/jdbc-cli-tool
> endless without any problems.
> so far so good.
[...]
> JBoss EAP 5.1.2 with connection pooling and xa-datasource/two-phase-commits
> (transactions on multiple datasources needed)
> *and* *<prepared-statement-cache-size>1000</prepared-statement-cache-size>*
>
> i can run the query four times with good performance and after that postgresql
> starts with the strange lseek() behavior.

It sounds like your bash script and JBoss are doing something different.
Would it be possible for you to turn on log_statements = 'all' in PG,
see what's different, and then update the bash/psql script to do exactly
what JBoss does, and see if you can reproduce it that way?

It certainly looks like a PG bug, but it'd be a lot easier to debug with
a simple, well-defined test case which shows the failure.

    Thanks!

        Stephen

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