Let’s start the move from DDS physical files to DDL tables. As you’ll see, there’s more to this move than a change of name. Keep reading to find out what changes!
By Rafael Victória-Pereira
If DDS physical files are the large container ships that hold your data in a turbulent and ever-changing sea of users, business logic, communications, and programs, SQL tables are the luxury yachts. They provide the same functionality as their DDS counterparts but offer a slew of additional features that IBM keeps increasing with each OS release. The many possibilities provided by the CREATE TABLE SQL instruction are the best proof of this silly little nautical metaphor. In a previous TechTip, I used a made-up Invoice Master physical file to explain the SELECT SQL instruction. In case you don’t remember, here’s a table describing the fields on that file: