MX 2.x)

ODBC/MX Client Overview

HP NonStop ODBC/MX Driver for Windows—527888-004

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Connection Pooling

the user context to the one defined in the configuration for the data source name on

the server.

Connection Pooling

Connection pooling can improve MXCS performance by allowing an ODBC application

to use (or reuse) a connection from a pool of connections without reestablishing the

connection.

The Microsoft ODBC driver manager maintains the connection pool by continuing to

hold a connection for a specified time after the client disconnects. During that time, if

the client sends another connection request that uses the same connection string, the

driver manager uses the same connection without sending another connection request

to the server. This can improve the connection response time and is especially useful

for web-based applications where connections to the same data source name occur

frequently.

Enabling Connection Pooling

The connection pooling mechanism is enabled by the client ODBC application. The

ODBC/MX client installation program (tdm_odbc.exe) automatically enables connection

pooling for the ODBC/MX driver by setting the CPTimeout value to 60 seconds in the

following Windows NT Registry entry:

HKEY_LOCAL_SYSTEM\Software\ODBC\ODBCINST.INI\

NonStop ODBC/MX\CPTimeout

To change CPTimeout to a different value for all ODBC/MX clients on the client

workstation, edit the CPTimeout Registry entry using the Registry Editor. To change

CPTimeout for only one session, call the SQLConfigDriver function.

If CPTimeout is zero (0), connection pooling is disabled for the ODBC/MX driver, even

if an application requests it.

Note. For an application to use connection pooling, the Connection Idle Timeout value for the

server data source to which the application will connect must be greater than the CPTimeout

value. The default is 10 minutes.

You set the Connection Idle Timeout value when you configure the data source using

NSM/web.