DB2

DB2 400 is the database built in to OS/400.

It can be accessed using two primary mechanisms ... SQL or directly from a high level language.

Features of DB2

Compared to how files could be structured and accessed on prior IBM and other platforms, DB2 had several revolutionary features that added to the potential programming power of the 400.

External Definition

Before the invention of this data base reality, we could only use Internal Definition of files. That means each and every program had to have its own layout of a file, and any dumps of the file showed all the data contigous, not breaking it up into meaningful fields. Forget about being able to access the data with programs like SQL.