Replace file specifications with your own field definitions.
By Joe Pluta
In my previous articles on this topic, I introduced extension files as a way to future-proof a legacy database and showed how to encapsulate those files in SQL access to allow growth. But I left out one important detail: When the compiler sees a file specification, it defines all the fields in that file. If you remove the F-spec, you have to define those fields yourself. And that's even trickier if you already have an extension file.