Re: Bound parameters on Linux are extremely slow (compared to unbound and/or Windows)

Just to make certain that we understand the setup. :-)

Machine:
A: PG-server OS: ?
B: Application client. Linux
C: Application client. Windows xx

--
Kim

On 26-05-2013 00:52, Reuven M. Lerner wrote:
> Hi, everyone. A project I'm assisting is connecting to PostgreSQL
> (9.2) via JDBC. We're experiencing extremely slow query execution,
> for precisely the same queries, depending on (a) operating system and
> (b) whether we use bind parameters.
>
> We're using two different Red Hat Linux systems (one running RHEL 5,
> and the other RHEL 6). The machines have 16 GB and 64 GB RAM,
> respectively, with 4+ GB allocated to shared buffers on each one.
> However, given that the performance difference is between psql and
> JDBC, I doubt that these are significant factors.
>
> We have two different Java programs (which do 1,000 inserts), each of
> which we've run 10 times on each of Windows and Linux. The average
> time needed for running each program is:
>
> Windows: 232 ms with binding, 152 ms without binding
> Linux: 2,233 ms (yes, 2.233 *seconds*) with binding, 176 ms without
> binding
>
> We've also run the same 1,000 inserts via psql on a remote machine,
> and the timing was quite fast (i.e., like what we saw on the Windows
> machine).
>
> The combination of binding + Linux seems to be the problematic one
> here, but I'm at a loss for why.
>
> I can provide the test programs if they'll help, but I'm first
> wondering where the problem might lie.
>
> Any suggestions or ideas? What additional information (e.g., the test
> programs) would help to track this problem down?
>
> Thanks in advance,
>
> Reuven
>