If statement caching is enabled for the data source, WebLogic Server caches prepared and callable statements that are used in each connection in the data source. Each connection has its own cache, but the caches for each connection are configured and managed as a group. When you clear the statement cache for a data source, you clear the statement cache for all connections in the instance of the data source you select. For more information, see Increasing Performance with the Statement Cache
To clear the statement cache in a JDBC data source:
Date source instances are listed by the server on which they are deployed.
Results are displayed at the top of the page, and the Status of Last Action is changed to SUCCESS for each data source that you selected to shrink.