FreeTDS Development Group

["Gad Hayisraeli" <gadh AT vmanage.com>]

> -----Original Message-----
> From: freetds-admin AT lists.ibiblio.org
> [mailto:freetds-admin AT lists.ibiblio.org]On Behalf Of Steve Langasek
> Sent: ?a 09 oaoaao 2003 20:54?
> To: freetds AT lists.ibiblio.org
> Subject: Re: [freetds] slow freetds-sybase perfromance - thorough test
>
>
> On Sun, Feb 09, 2003 at 04:52:12PM +0200, Gad Hayisraeli wrote:
> > finally i see HUGE speed boost, after setting packet size to 2048 in
> > ASE server and freetds client + ASE odbc driver:
>
> > maybe a new topic:
> > ====================
> > i did my tests on local network, so i can choose large packet sizes ,
> > but if the ASE is on another lan/wan network, could i choose the same
> > size, although the tcp packet size is less than local network ?
> > (indeed i chose 2048 on local net, where the default tcp packet size
> > is 1500 ...)
>
> 1500 is not a "default packet size", it's an MTU -- the *maximum*
> transmission size possible for a packet that fits within a single
> ethernet frame on a 10Mbps or 100Mbps ethernet.
>
> What are you doing in order to change the packet size?  It's possible
> that this has no direct relation to the size of packets on the wire.
> Indeed, if freetds is sending 2048-byte packets, they *will* be
> fragmented on ethernet, so I'm not sure how using such large tcp packets
> will improve performance.
>

i started the sybase central java edition and in the database configuration 
(right click on the db name) i choose
network parameters and changed the maximum packet size to be 2048.
in the freetds.conf, on client side, i changed the packet size to be 2048 as 
well

you were right about the tds packets - the packets that i saw in the 
freetds.log were :
create table - 544 bytes
insert into -  735 bytes

so this might be the cause for the performance degradation , and also it 
explains the huge change in performance between
14 and 13 coulmns , cause i think in the 13 columns case it was below 512 
bytes ...


Gad