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Q166083: INF: How to Enable Connection Pooling in an OLE DB Application

Article: Q166083
Product(s): Open Database Connectivity (ODBC)
Version(s): WINDOWS:1.1,3.0
Operating System(s): 
Keyword(s): kbprogramming
Last Modified: 25-AUG-1999

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The information in this article applies to:

- Microsoft Open Database Connectivity, version 3.0 
- Microsoft OLE DB, version 1.1 
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SUMMARY
=======

This article describes how to enable ODBC connection pooling in an OLE DB
application.

MORE INFORMATION
================

An OLE DB application can enable ODBC connection pooling if the OLE DB
application is using the OLE DB provider for ODBC. The OLE DB application that
uses the ODBC provider is like an ODBC application because the ODBC provider
internally calls the ODBC API to perform data manipulation.

The ODBC provider does not expose any property to allow an OLE DB application to
enable connection pooling. In order to enable connection pooling, the OLE DB
application needs to use the ODBC API to enable connection pooling before using
the ODBC provider. Because connection pooling is a process-level attribute, any
subsequent connection made through the ODBC provider will be using connection
pooling.

The following code demonstrates how an OLE DB application can enable connection
pooling:

     SQLAllocEnv(&henv);

     //enable connection pooling
        SQLSetEnvAttr(
           NULL,
           SQL_ATTR_CONNECTION_POOLING,
           (SQLPOINTER)SQL_CP_ONE_PER_DRIVER,
           SQL_IS_INTEGER);

     SQLAllocConnect(henv,&hdbc);

     // connect to the OLE DB ODBC provider
           OleInitialize(NULL);
  ...
        hr = CoCreateInstance( CLSID_MSDASQL, NULL, CLSCTX_INPROC_SERVER,
           IID_IDBInitialize, (void **)&pIDBInit );
  ...
        CoUninitialize();
     //finish OLE DB stuff

       SQLFreeConnect(hdbc);
       SQLFreeEnv(henv);

     //disable connection pooling
        SQLSetEnvAttr(
           NULL,  // make process level cursor pooling
           SQL_ATTR_CONNECTION_POOLING,
           (SQLPOINTER)SQL_CP_OFF,
           SQL_IS_INTEGER);

Additional query words: viper asp pool ado

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Keywords          : kbprogramming 
Technology        : kbAudDeveloper kbODBCSearch kbOLEDBSearch kbOLEDB110 kbODBC300
Version           : WINDOWS:1.1,3.0
Issue type        : kbhowto

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