Following is a summary of the best practices when tuning data sources.
Configuring the Connection Pool
To avoid connection delays due to on-demand creation of connections, Oracle recommends you set the value of the Initial Capacity parameter to the value of the Maximum Capacity parameter when configuring a connection pool. You can estimate the value of the Maximum Capacity parameter through load-testing exercises. However, beware of oversimplifying and making your application deployment too tightly bound to one particular configuration.
You can use the <pool-name> mechanism for setting a <max-threads-constraint>, as shown in the following example, which shows part of a weblogic-ejb-jar.xml file:
</weblogic-ejb-jar> - <work-manager> ...