FreeTDS Development Group

["Lowden, James K" <LowdenJK AT bernstein.com>]

> From: Steve Langasek [mailto:vorlon AT netexpress.net]
> Sent: February 5, 2003 11:20 AM
> 
> The two lines I see that directly compare FreeTDS
> to the Windows driver without changing any other variables are these:
>
> linux         fastlinux       yes     odbc++ over freetds     1.587
16.38
> windows       fastlinux       yes     odbc++ over ASE odbc    0.753   34

Also interesting:

fastlinux       fastlinux       local  odbc++ over freetds       1.57
16.56 
linux   fastlinux       yes     odbc++ over freetds      1.59    16.38 

Indicates that for this test FreeTDS is almost unaffected by the presence of
a network, when using TDS 5.0.  Or is it 4.2, Gad?  

If we accept that the FreeTDS linux client is 50% as fast as the the windows
client, then this pair is very weird (which is how Gad got started, right?):

linux           windows         yes     odbc++ over freetds      5.28
4.92 
windows         windows         local   odbc++ over ASE odbc     0.14
185.00 

Something is clearly, um, suboptimal here.  Microsoft has the opportunity to
use shared memory (or a giant packet size) on the local server, and well
might.  Even so, it's still hard to explain the difference.  One would
suppose the Linux client could at least approach the 16 lps speed it had
with the Linux server.  

I hope you can get FreeTDS working on your Win32 client, so we can see the
apples-to-apples comparison.  If you have a nonlocal windows client
available, that would help too.  That would reintroduce the network, and
it's possible that Sybase on Win32 has poor network characteristics.  

Just to double check: Are you using FreeTDS 0.60?  If so, you really should
get last night's snapshot (don't use rc1).  We discovered a bug some time
ago that caused FreeTDS to write to the log file even when it should not.
That would definitely affect performance, and is consistent with the "wide
tables are slower" observation.  Also, 

> freetds trace  = yes
> freetds trace level = 10

If "freetds trace  = yes" means "dump file = /tmp/freetds.log" in
freetds.conf, that's a problem, because you're logging your queries, which
is very expensive.  

Thank you for the data, Gad.  Yours is the first objective measure I can
recall.  

--jkl


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