8.4 Application considerations for performance in database access

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8.3 Enterprise JavaBeans

In this section, we discuss EJB performance considerations as they apply to accessing a DB2 database.

8.3.1 EJB performance considerations

From a database perspective, the following considerations apply.

• EJB 2.0 module

  In general, read-only methods and optimistic locking will provide better performance. However, be careful with the use of optimistic locking since problems may only become apparent under heavy load and hence may not be found in development.

  A common mistake is just using the default setting. This might cause performance issues.

• EJB 1.1 module

  • Ensure that the Isolation level attributes setting selection is based on the minimal semantic requirements of the application. In most cases, this corresponds to Read Committed on the Java side, which translates to Cursor Stability on the DB2 side.

  • Ensure that the Access Intent is set to Read for all EJB read only methods.

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