Re: PostgreSQL, and ODBC statement handles

Hi Reza,

How are you setting 'Threading' in odbcinst.ini?

regards,
Hiroshi

On 2017/05/04 14:08, Reza Taheri wrote:
>
> I am running a benchmark (TPCx-V) with a single process on the client
> system handing all the load. Each connection to the server is in a
> separate thread with its own connection to PGSQL, and its own
> connection handle and statement handle. I am facing a contention
> problem with ODBC on the client side. strace and perf top show we are
> serializing over what appears to be accesses to the ODBC statement
> handlepgsq. Contention goes away if I use multiple processes instead
> of multiple threads within a process.
>
> I suppose I don’t understand the concept of “handles” well, but I am
> surprised that all the threads get the same connection handle number
> and the same statement handle number. Does that mean some data
> structure is shared between the different threads? Is there a way to
> force different statement handles (or handle numbers???) for different
> threads within one process? I have asked this question on the ODBC
> mailing list, and they suggested it could be something in the
> postgresql driver. I can provide detailed performance data, but maybe
> someone can help me figure out what might be a very basic
> configuration or parameter setting problem. I am running the following
> RPMs on RHEL 7.1:
>
> postgresql93-9.3.5-2PGDG.rhel7.x86_64
>
> postgresql93-odbc-09.03.0300-1PGDG.rhel7.x86_64
>
> unixODBC-2.3.1-10.el7.x86_64
>
> Thanks,
> Reza
>