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Teacher Birgitta Hauser

Title: Create or Replace … DDS Files with DDL Objects

ABSTRACT: With the latest releases and technology refreshes the SQL data definition language (DDL) for
creating and maintaining database objects was enormously enhanced. DDS on the other hand is stabilized. But still a lot of applications even those with a modern graphical interface and where the latest goodies of the programming language are used in the source code are based on DDS described files.

The excuse DDL enhancements cannot be used, because of the DDS description and the native I/O access of these files, does not count any more. With Reverse Engineering, the SQL code for DDS described objects can be retrieved.
CREATE OR REPLACE statements allow DDS described physical and logical files to be converted into SQL defined database objects, while the programs that use these files can stay untouched. With the CREATE OR REPLACE TABLE statement, files with fields based on field reference tables can be managed.

Converting from DDS to DDL is the first but necessary step when modernizing the database
objects used within IBM i applications. After conversion all the new features integrated in
SQL in the Db2 for i can be used and finally it is even possible to re-normalize the database

Learning Objectives:

In this session you will learn to convert DDS described files into SQL tables and SQL indexes without touching any program code. It will also be demonstrated how reference files can be used in composition with SQL tables and how (future) enhancements, for example adding columns on a specific position or changing data types and lengths can be managed.
It is also demonstrated how to manage tables that are based on field reference tables, even though SQL does not directly support field reference tables.


Database Engineers, Database Administrators, Managers and Programmers who want to
modernize their database and want to start with converting the existing DDS described files
into SQL objects.

Level: Advanced

Duration: Single Session

  • CREATE OR REPLACE TABLE - Enhancements

  • Reverse Engineering

  • Demo: Converting DDS described Files into DDL defined Database Objects

    • Convert DDS described physical files into SQL Tables

    • Adding long more descriptive SQL Column and Object Names

    • Convert DDS described logical Files into SQL Indices

    •  What about our RPG/Cobol Programs with native I/O?

  • SQL Tables based on Field Refence Files

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