Re: setFetchSize() [Viruschecked] - Mailing list pgsql-jdbc

From Felipe Schnack
Subject Re: setFetchSize() [Viruschecked]
Date
Msg-id 20030717142245.2f6f4195.felipes@ritterdosreis.br
Whole thread Raw
In response to Re: setFetchSize() [Viruschecked]  ("Patric Bechtel" <bechtel@ipcon.de>)
List pgsql-jdbc
oh, so pgsql is the problem, not the driver?
  If I understand what you said well, I just have to turn off autocommit and set fetchsize to any positive number and
thedriver will do its work, right? 

On Thu, 17 Jul 2003 19:11:44 +0200
"Patric Bechtel" <bechtel@ipcon.de> wrote:

> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> On Thu, 17 Jul 2003 13:01:43 -0400, Dmitry Tkach wrote:
>
> Hello Dmitry,
>
> that's exactly what the driver is doing if you do a setFetchSize(10).
> Nevertheless, it won't solve the problem of the server eating HUGE amounts of memory if you do a "declare foo cursor
forselect * from myhugetable". It seems  
> like postgresql locks all rows (or even copies them around in memory) until the connection drops again.
>
> Patric
>
> >Rich Cullingford wrote:
>
> >> All,
> >> Will this function be implemented in Release 7.4? I have several arge
> >> tables that run Java out of memory when I attempt to load them through
> >> JDBC. Any workarounds arppreciated...
>
> >I was using cursors for a while as a workaround...
> >Something like this:
>
> >c.setAutocommit (false);
> >Statement s = c.createStatement ();
> >s.execute ("declare foo cursor for select * from bar");
>
> >while (true)
> >{
> >    ResultSet rs = s.executeQuery ("fetch 10 from foo");
> >    int count = 0;
> >    while (rs.next ())
> >    {
> >        count++;
> >        doStuffWithThisRow (rs);
> >     }
> >
> >     if (count < 10) //The whole cursor contents has been processed
> >          break;
> >}
> >
> >
> >I hope, it helps...
>
> >Dima
>
>
>
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