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We are in the process of upgrading from Sybase v9 to v11, and I am having issues with the v11 odbc driver for a couple connections. I am seeing performance taper after approx. 500MB of data is transferred.

I am performing all tests on the same windows 2008r2 server, using SQL Server Integration Services 2012 to connect and pull data. I have two 32bit (but am seeing same results with 64bit v11) system odbc connections, one for the v9 drivers and one for the v11 drivers. Both are configured for the same Sybase v11 database, with the same settings. I am pulling two different data sets in parallel that total roughly 1GB.

I am seeing a steady average of roughly 3MB/s with the v9 drivers. 1GB of data is taking approx. 350sec to transfer.

The v11 drivers start to taper around 500MB, going from 3MB/s to < 1MB/s. It ends up taking roughly 4000 seconds to finish transferring the 1GB of data.

Does anyone have any suggestions or information? I didn't find anything that seems to relate to this in the connection parameters or network protocol options of the documentation. Additionally, it doesn't seem there is a meaningful difference in the connection logs below.


ODBC Log for v9:

Mon Sep 30 2013 14:55:50
14:55:50 Application information:
14:55:50 "HOST=*;OS=Windows NT 6.1 Build 7601 Service Pack 1;PID=0x1d70;THREAD=0x7e0;EXE=C:\Program Files (x86)\Microsoft SQL Server\110\DTS\Binn\ISServerExec.exe;VERSION=;API=ODBC;TIMEZONEADJUSTMENT=-240"
14:55:50 Attempting to connect using:
UID=*;PWD=********;ENG=*;START=*;CON=SQL_DBC_135108e8;ASTOP=NO;INT=NO;DBG=YES;LOG=C:\Sybase Drivers\ODBC_ASA9.log;DMRF=NO;LINKS=SharedMemory,TCPIP{ip=};COMP=NO
14:55:50 Attempting to connect to a running server...
14:55:50 Trying to start TCPIP link ...
14:55:50 Loading wsock32.dll
14:55:50 Loading ws2_32.dll
14:55:50 TCP using Winsock version 2.0
14:55:50 My IP address is
14:55:50 My IP address is
14:55:50     TCPIP link started successfully
14:55:50 Attempting TCPIP connection (no asasrv.ini cached address)
14:55:50 Looking for server with name *
14:55:50 Trying to find server at address
14:55:50 Found server, verifying server name
14:55:50 Found database server at address
14:55:50 Found database server * on TCPIP link
14:55:50 Connected using client address
14:55:50 Connected to server over TCPIP at address
14:55:50 Writing server address to asasrv.ini cache
14:55:50 Connected to ASA Engine version
14:55:50 Connected to the server, attempting to connect to a running database...
14:55:50 [  307] Connected to database successfully

**ODBC Log for v11:**
Mon Sep 30 2013 14:54:41
14:54:41 Attempting to connect using:
UID=*;PWD=********;DBN=*;ENG=*;CON=SQL_DBC_114a7948;ASTOP=NO;INT=NO;CBSIZE=1460;DBG=YES;LOG='C:\Sybase Drivers\ODBC_ASA11.log';DMRF=NO;LINKS='SharedMemory,TCPIP{ip=}';COMP=NO
14:54:41 Attempting to connect to a running server...
14:54:41 Trying to start TCPIP link ...
14:54:41 TCP using Winsock version 2.2
14:54:41 My IP address is
14:54:41 My IP address is ::1
14:54:41 My IP address is
14:54:41     TCPIP link started successfully
14:54:41 Attempting TCPIP connection (address found in sasrv.ini cache)
14:54:41 Trying to find server at cached address without broadcasting
14:54:41 Found server, verifying server name
14:54:41 Found database server at address
14:54:41 Found database server * on TCPIP link
14:54:41 Connected using client address
14:54:41 Connected to server over TCPIP at address
14:54:41 Connected to SQL Anywhere Server version
14:54:41 Application information:
14:54:41 IP=;HOST=*;OSUSER=*;OS='Windows 2008R2 Build 7601 Service Pack 1';EXE='C:\Program Files (x86)\Microsoft SQL Server\110\DTS\Binn\ISServerExec.exe';PID=0x1f2c;THREAD=0x1f7c;VERSION=;API=ODBC;TIMEZONEADJUSTMENT=-240
14:54:41 Connected to the server, attempting to connect to a running database...
14:54:41 [  304] Connected to database successfully

asked 30 Sep '13, 15:56

enjay's gravatar image

accept rate: 0%

edited 30 Sep '13, 16:19

Graeme%20Perrow's gravatar image

Graeme Perrow

Comment Text Removed

What operation is being used to "pull data"?

On the SQL Anywhere side, what operation is being used to satisfy the pull? Is there a problem with query plan?

(01 Oct '13, 08:39) Breck Carter
Replies hidden

Both are queries that result in table scans with a LOWER function on one column in the projection. I need a couple columns from every row, so this is expected.

However, the degradation only occurs with the v11 drivers. v9 drivers with the v11 database work as expected.

(01 Oct '13, 08:59) enjay

While using CBSIZE=1460 should cause both 9 and 11 to use the same packet size, given you are transferring so much data, I would expect the 11 default of 7300 to be faster. I would also expect the maximum of 16000 to be faster yet.

Also, can you double check that ODBC tracing is disabled in the v11 case.

Other than ODBC tracing, I have no idea what could cause this slowdown.

(01 Oct '13, 09:36) Ian McHardy
Replies hidden

I tested with three different CBSIZE settings (1460, 7300, 16000) and am seeing the slowdown at approx 500MB with all three. ODBC tracing is off. Thanks for the suggestions.

(01 Oct '13, 10:36) enjay

Have you been able to solve this?

(23 Oct '13, 06:07) Martin

Try removing the CBSIZE=1460 since the default is 7300 for everything except Windows Mobile.

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answered 01 Oct '13, 09:33

Breck%20Carter's gravatar image

Breck Carter
accept rate: 20%

Well, that may be added for compatibility, because for v10 and below 1460 was the default value on all platforms...

(01 Oct '13, 09:36) Volker Barth

Sorry, I should have mentioned that I got the same performance issues with 7300 CBSIZE. It was at that initially, and I changed to 1460 since that was the only difference I saw in settings between the drivers. I am going to change both to the maximum setting since it's server to server, but I don't think this will eliminate the slowdown. I will verify. Thanks for the suggestion.

Edit: I am seeing the same results with buffer sizes of 1460, 7300, and 16000.

(01 Oct '13, 10:02) enjay

I have a similar issue that I am dealing with. I suspect that the newer Sybase ODBC drivers have some type of negative interaction with windows tcp auto tuning. If you disable windows tcp auto tuning, you get some improvement. There is a known defect in Windows Server 2008 R2 (and on Win 7 machines) related to windows tcp auto tuning.

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answered 05 Mar '15, 21:00

JimKazmer's gravatar image

accept rate: 0%

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question asked: 30 Sep '13, 15:56

question was seen: 4,498 times

last updated: 05 Mar '15, 21:00