PRB: SQL PacketSize Property May Not Work w/Individual Handles (137536)

SYMPTOMS

After you use the SQLSETPROP command to change the packet size of an ODBC connection, the SQLGETPROP command for the packet size returns the original value of the packet size. The expected behavior is that SQLGETPROP would return the new packet size as set in the SQLSETPROP command.

CAUSE

This behavior occurs because some drivers and servers do not support changing the packet size on an active connection. In these situations, it is necessary to change the default packet size prior to making each connection. This is discussed in detail in the "Workaround" section of this article.

RESOLUTION

The following workaround precludes setting up ODBC data sources connect1 and connect2. These can be SQL, Oracle, or other ODBC connections.

Use the following commands to set individual packet sizes:

   =SQLSETPROP(0,'packetsize',8192) && 0 means default handle
   handle1=SQLCONNECT('connect1','username','password')
   paksize1=SQLGETPROP(handle1,'packetsize')

NOTE: packsize1 will return 8192

   =SQLSETPROP(0,'packetsize',4096) && 0
   handle2=SQLCONNECT('connect2','username','password')
   paksize2=SQLGETPROP(handle2,'packetsize')

NOTE: packsize2 will return 4096

MORE INFORMATION

The following steps illustrate the behavior of ineffective, individual packet size settings:

Steps to Reproduce Behavior

   handle1=SQLCONNECT('connect1','username','password')
   =SQLSETPROP(handle1,'packetsize',8192 &&
   paksize1=SQLGETPROP(handle1,'packetsize')

NOTE: packsize1 will return 4096

   handle2=SQLCONNECT('connect2','username','password')
   =SQLSETPROP(handle2,'packetsize',8192 &&
   paksize2=SQLGETPROP(handle2,'packetsize')