Summary

The focus of this chapter was to highlight important DB2 application development features that are not part of the SQL PL language, but are frequently employed in DB2 application objects to improve performance and simplify SQL PL application development.

You saw how advanced SQL can be used to access internal transition tables by combining SELECTs with INSERT, UPDATE, and DELETE, and how MERGE can simplify the task of merging data from two tables. The concept of declared global temporary tables was introduced, as well as a lesser known technique for sharing temporary tables between the application and other procedures. Save points can be employed to partially rollback transactions. Finally, an example of how to encapsulate sequence objects was presented for applications that want to maintain a high degree of database independence.