Release 10.1A: OpenEdge Development:
ADM Reference

KeyFields

Comma-separated list of the key fields. The indexInformation is used to try to figure out the default KeyFields list, but this is currently restricted to conditions:

The First Table in the join is the only enabled table.
All the fields of the index are present is the SDO.
The following index might be selected:
Primary index if unique.
First Unique index.
There is currently no check whether the field is mandatory.
Data type: CHARACTER
Notes: Read and Write