Обсуждение: Prepared statement does not exist

--- On Thu, 19/3/09, Nimesh Satam <nimesh.zedo@gmail.com> wrote:
>
> We are receving the following error in the postgres
> database logs:
>
> 2009-03-19 02:14:20 PDT [2547]: [79-1] LOG:  duration:
> 0.039 ms  statement:
> RESET ALL
> 2009-03-19 02:14:20 PDT [2547]: [80-1] LOG:  duration:
> 0.027 ms  statement:
> SET SESSION AUTHORIZATION DEFAULT
> 2009-03-19 02:14:20 PDT [2547]: [81-1] ERROR:  prepared
> statement "S_1" does
> not exist
> 2009-03-19 02:14:20 PDT [2547]: [82-1] STATEMENT:
> DEALLOCATE "S_1"
> 2009-03-19 02:14:20 PDT [2547]: [83-1] ERROR:  prepared
> statement "S_4" does
> not exist
> 2009-03-19 02:14:20 PDT [2547]: [84-1] STATEMENT:
> DEALLOCATE "S_4"
>
> We receive this errors when we start connecting the java
> application
> thorugh pgpool. What causes this problem and how can it be
> avoided?

Looks like your app is dissconnecting from pgpool which is causing pgpool to send the RESET ALL, this will deallocate
theprepared statement. Then the app is reconnecting to pgpool again and expecting the prepared statement to still be
available,which it will not be. 

Glyn Astill,

Thank for your reply. But can you confirm on this? As what I see from
the logs, its pgpool which is trying to deallocate the prepared
statement and not the application. The application just disconnects
and not tyring to use the same connection.

Regards,
Nimesh.

--- On Fri, 20/3/09, Nimesh Satam <nimesh.zedo@gmail.com> wrote:

> From: Nimesh Satam <nimesh.zedo@gmail.com>
> > > We are receving the following error in the
> postgres
> > > database logs:
> > >
> > > 2009-03-19 02:14:20 PDT [2547]: [79-1] LOG:
> duration:
> > > 0.039 ms  statement:
> > > RESET ALL
> > > 2009-03-19 02:14:20 PDT [2547]: [80-1] LOG:
> duration:
> > > 0.027 ms  statement:
> > > SET SESSION AUTHORIZATION DEFAULT
> > > 2009-03-19 02:14:20 PDT [2547]: [81-1] ERROR:
> prepared
> > > statement "S_1" does
> > > not exist
> > > 2009-03-19 02:14:20 PDT [2547]: [82-1] STATEMENT:
> > > DEALLOCATE "S_1"
> > > 2009-03-19 02:14:20 PDT [2547]: [83-1] ERROR:
> prepared
> > > statement "S_4" does
> > > not exist
> > > 2009-03-19 02:14:20 PDT [2547]: [84-1] STATEMENT:
> > > DEALLOCATE "S_4"
> > >
> > > We receive this errors when we start connecting
> the java
> > > application
> > > thorugh pgpool. What causes this problem and how
> can it be
> > > avoided?
> >
> > Looks like your app is dissconnecting from pgpool
> which is causing pgpool
> > to send the RESET ALL, this will deallocate the
> prepared statement. Then the
> > app is reconnecting to pgpool again and expecting the
> prepared statement to
> > still be available, which it will not be.
>
> Thank for your reply. But can you confirm on this? As what
> I see from
> the logs, its pgpool which is trying to deallocate the
> prepared
> statement and not the application. The application just
> disconnects
> and not tyring to use the same connection.

There is the possibility that it's pgpool sending the deallocate in error after the reset all then. Either way, this is
notrelevent to the performance list, send it over to the pgpool list... and tell them your pgpool version number too -
itmay be a fixed bug.