[Progress Communities] [Progress OpenEdge ABL] Forum Post: RE: How to add a FOREIGN KEY to an existing table?

[gus bjorklund]

The term "Primary Index" in the 4GL predates the first SQL standard. It was originally intended to be the index that was used for 4GL queries as the "default index", used when there was no other information, such as the terms of a where clause, that could be used to choose another more suitable index. As dmitri says, it has nothing to do with primary keys.

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