> Obviously, many indexes are unique and thus won't have duplicates at
> all. But if someone creates an index and doesn't make it unique, odds
> are very high that it has some duplicates. Not sure how many we
> typically expect to see, but more than zero...
Peter may not, but I personally admin lots of databases which have
indexes on values like "category" or "city" which have 100's or 1000's
of duplicates per value. I don't think this is uncommon at all.
--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com