Re: Degradation of performance when upgrade psqlodbc to 09.03.0400

Hi,

I have tested some version of psqlODBC between 09.00.0310 ~ 09.03.0400,
and found that exactly version 09.03.0100 made the degradation of performance
in executing my batch (it is not related to replication, i found that).

I will try to find out which commit did it and how to avoid this issues.

Thanks and best regards.
bocap

> On Feb 5, 28 Heisei, at 07:29, Dang Minh Huong <kakalot49(at)gmail(dot)com> wrote:
>
> Hi,
>
> Thanks for prompt response sir.
>
>>> On 04/02/16 16:54, Dang Minh Huong wrote:
>>> I'm using psqlodbc version 09.00.0310 for my project. Recently i tried to upgrade to version 09.03.0400 and found that it is very slow in processing my batch (batch with milion of SELECT, UPDATE, INSERT statements).
>>>
>>> [environment]
>>>
>>> OS: Redhat 6.7 x 2 nodes
>>>
>>> PostgreSQL 9.1.19: Synchronouse Streaming replication & hot_standby.
>>>
>>> DB connect method: psqlodbc/unixODBC.
>>>
>>> [results of performance]
>>>
>>> It took below timing to execute my batch
>>>
>>> In version 09.00.0310: 11minute
>>>
>>> In version 09.03.0400: 53minute
>>>
>>> When my batch run in 09.03.0400, ps command repeatedly show below processes.
>>>
>>> Something delay the transmitting & replaying WAL in STANDBY db node?
>>>
>>> -----
>>>
>>> ... UPDATE waiting for 0/xxx
>>>
>>> or
>>>
>>> ... INSERT waiting for 0/yyy
>>>
>>> ------
>>>
>>> Note that, my replication connection is working well, and above messages just display within a second. This phenomenon is not reproduced in version 09.00.0310.
>>>
>>> I have confirmed release note. I thought changing of UseServerSidePrepare's default value made this perfomance problem but not. I don't know what change make it slower.
>>>
>>> Sorry for lack of infomation but, is any big changes related to performance between above versions?
>>
>> I don't recall anything relevant. It seems strange that changing the ODBC driver would make any difference to the replication.
>
> I also think that. I wonder if something missed in my environment but not found, and it is not reproduced in 9.00.0310.
>
>> Something to do with autocommit, perhaps?
>
> Sorry but did you mean that, default of autocommit was changed to "on", between above versions?
>
> Thanks and best regards,
> bocap.
>
>>
>> - Heikki