A connection pool

To improve the performance and scalability of your application, you can obtain your connection to the database server through a DataSource object that references a ConnectionPoolDataSource object. Informix® JDBC Driver provides a Connection Pool Manager as a transparent component of the ConnectionPoolDataSource object. The Connection Pool Manager keeps a closed connection in a pool instead of returning the connection to the database server as closed. Whenever a user requests a new connection, the Connection Pool Manager gets the connection from the pool, avoiding the overhead of having the server close and re-open the connection.

Using the ConnectionPoolDataSource object can significantly improve performance in cases where your application receives frequent, periodic connection requests.

For complete information about how and why to use a DataSource or ConnectionPoolDataSource object, see the JDBC 3.0 API.
Important: This feature does not affect IfxXAConnectionPoolDataSource, which operates under the assumption that connection pooling is handled by the transaction manager.