WebSphere Application Server data source properties

You can set the properties that apply to the WebSphere Application Server connection, rather than to the database connection, by selecting the WebSphere Application Server data source properties link under the Additional Properties section of the data source configuration page.

• Statement Cache Size: Specify the number of prepared statements that are cached per connection. A prepared statement is a precompiled SQL statement that is stored in a prepared statement object. This object is used to execute the given SQL statement multiple times. The WebSphere Application Server data source optimizes the processing of prepared statements. In general, the more statements your application has, the larger the cache should be. For example, if the application has five SQL statements, set the statement cache size to 5, so that each connection has five statements.


• Enable multithreaded access detection :If you enable this feature, the application server detects the existence of access by multiple threads.


• Enable database reauthentication: Connection pool searches do not include the user name and password. If you enable this feature, a connection can still be retrieved from the pool, but you must extend the DataStoreHelper class to provide implementation of the doConnectionSetupPerTransaction() method where the reauthentication takes place. Connection reauthentication can help improve performance by reducing the overhead of opening and closing connections, particularly for applications that always request connections with different user names and passwords.


•  Manage cached handles: When you call the getConnection() method to access a database, you get a connection handle returned. The handle is not the physical connection, but a representation of a physical connection. The physical connection is managed by the connection manager. A cached handle is a connection handle that is held across transaction and method boundaries by an application. This setting specifies whether cached handles should be tracked by the container. This can cause overhead and only should be used in specific situations. For more information about cached handles, see the Connection Handles topic in the Information Center.


• Transaction context logging: The J2EE programming model indicates that connections should always have a transaction context. However, some applications do not have a context associated with them. This option tells the container to log that there is a missing transaction context in the activity log when the connection is
  obtained.


• Pretest existing pooled connections: If you check this box, the application server tries to connect to this data source before it attempts to send data to or receive data from this source. If you select this property, you can specify how often, in seconds, the application server retries to make a connection if the initial attempt fails. The pretest SQL string is sent to the database to test the connection.


• Pretest new connections: If you check this box, the application server test the initial connection to database. If you select this property, you specify how often, in seconds, the application server retries to make a connection and how many times it tries. The pretest SQL string is sent to the database to test the connection.