Native optimizations are a set of functions that make the IBM® Toolbox for Java™ classes work the way a user would expect them to work when running on i5/OS™. The optimizations affect operation of IBM Toolbox for Java only when running on the iSeries™ JVM.
It is very important to understand that your Java programs use native optimizations only when you use the version of IBM Toolbox for Java that matches the version of i5/OS on your server. The optimizations are:
- Signon: When no userid or password is specified in the AS400 object, the userid and password of the current job are used
- Directly calling i5/OS APIs instead of making socket calls to host servers:
- Record-level database access, data queues and user space when security requirements are met.
- Program call and command call when security requirements and thread safety requirements are met.
No change to the Java application is needed to get the optimizations. IBM Toolbox for Java automatically enables the optimizations when appropriate.
Native optimization compatibility requirements
The following table shows which versions of IBM Toolbox for Java LPP and i5/OS you must run to use native optimizations. This table documents only compatibility issues that affect native optimizations. For general compatibility issues, see Compatibility with different levels of i5/OS.
| Level of i5/OS | IBM Toolbox for Java LPP required to use native optimizations |
|---|---|
| V5R2 | 5722-JC1 V5R2M0 |
| V5R3 | 5722-JC1 V5R3M0 |
 V5R4 |
5722-JC1 V5R4M0 |
In order to gain the performance improvements, you need to make sure to use the jar file that includes i5/OS native optimizations. For more information, see Note 1 in Jar files.
When the versions of IBM Toolbox for Java and i5/OS do not match, native optimizations are not available. In this case, IBM Toolbox for Java works as if it is running on a client.