This part of the memory is optional, and you may not need it if you are not storing any Java Stored Procedures. However, in general, this part can be important for the instance, especially since there are several standard Oracle-supplied components written in Java.

The Java Pool is controlled by three parameters:

1. JAVA_POOL_SIZE: This parameter is used to create and control the size of the Java Pool. The default value for this parameter is typically 24MB, but it is constrained by another parameter, which is SGA_MAX_SIZE. This parameter can be modified without shutting down the database.
2. JAVA_MAX_SESSIONSPACE_SIZE: This is a static parameter used to define the amount of memory in the Java Pool that any given session can use.
3. JAVA_SOFT_SESSIONSPACE_LIMIT: This is also a static parameter. It helps monitor the usage of the Java Pool before reaching the limit defined by JAVA_MAX_SESSIONSPACE_SIZE. If a session exceeds the value defined in this parameter, a message will be sent to the Trace File.

You can monitor the Java Pool using the V$SGASTAT view.