> The references are all to the same table i.e. they are employee ids, so
> leaving some and not others would make no sense. The table has no
> deletes, small amount of inserts and moderate amount of updates. However
> there are many selects and its their performance I am most concerned with.
Foreign keys have no impact on selects.
Although this does sound like a rather strange design to me (20+ columns
wide and they're all employee ids?)
