Re: 500 times slower

> -----Original Message-----
> From: pgsql-odbc-owner@postgresql.org
> [mailto:pgsql-odbc-owner@postgresql.org] On Behalf Of Karol Szkudlarek
> Sent: 09 February 2005 11:48
> To: Karol Szkudlarek
> Cc: pgsql-odbc@postgresql.org
> Subject: Re: [ODBC] 500 times slower
>
> Karol Szkudlarek wrote:
> >
> > The problem exists only between windows client and remote windows
> > server. The other configurations (for example remote linux server)
> > works ok. We are using stable version of psqlodbc driver.
> >
> > ---------------------------(end of
> broadcast)---------------------------
> > TIP 7: don't forget to increase your free space map settings
>
> Hi!
>
> My collegue spent some time to dig the following case and it
> looks like
> Nagle algorithm and delayed ACKs related problem.
> In psqlodbc.h
> #define SOCK_BUFFER_SIZE            4096
>
> I changed that value to 8192 and driver works fine for me.
> I am not sure why this change helps.

Err, no neither am I. Why do you think it's got something to do with
Nagle/delayed ACKs?

The only thing that instantly rings bells for me is that the max size of
a text field is 8190 bytes at present (which really should be increased,
if not removed altogether), which won't fit in the default buffer. But
then, I wouldn't expect to see the performance drop you describe with a
4096 byte buffer, only one much smaller.

Anyone else got any ideas?

Regards, Dave