Develop any customized user-defined functions or stored procedures to replace proprietary functions
Document and implement any logic or functionality in the application code that couldn't be ported in a database application object
Database application objects (stored procedures, triggers, and user-defined functions) are essentially business logic contained within the database. Usually these objects are written in a native SQL procedural language or a higher-level language that must be compiled and associated/bound to the target database for use. Often, some portion of these objects will have to be rewritten or, in extreme cases, moved to the application code in order to preserve the functionality of the source system. As a result, this step is usually one of the most time consuming and expensive in the porting process.
Retrieving the database application object definitions can often occur at the same time that the database structure is captured if the objects are written in an SQL-like procedural language and stored within the database. For objects written in higher-level languages (Java, C, and so on), this involves copying the source files to the DB2 system, and finding a compatible compiler and binding mechanism. This is usually a manual process. If SQL statements are embedded in these objects, they can sometimes be extracted and run through a porting or migration tool that can convert the syntax so that it is compatible with DB2. After that, the converted statements can be put back in the original code, and then compiled with the supported compiling and binding mechanism.
After converting the database application objects, extensive testing should be performed on the converted objects. This means that test data is needed before testing can occur. This would require that you do at least some of the work in Step 11. Data migration before you complete this step.
After the conversion is completed, some adjustments or tweaks may still be required. For example, if the code was converted using a tool, small adjustments might be needed to improve performance.
