Bruce,
> Do they? We don't create an index automatically when using REFERENCES.
> We do create an index for PRIMARY KEY.
>
> I was just wondering if the REFERENCES column is more sensitive to join
> usage and would benefit from more accurate statistics even if it doesn't
> have an index.
I don't think so. If one does not create an index on an FK column, this is
usually because the column does not have enough of a range of values to
deserve indexing (for example, 4 potential values across 100,000 records).
In that case, we would not want to up the statistics either.
And we haven't made it a practice to hand-hold for database designers who
don't know when to index, so I don't think we should start now.
--
-Josh BerkusAglio Database SolutionsSan Francisco