Thank you Don. So far, my experiments with UNION have resulted
in slow queries... but I keep discovering new SQL stuff as I solve
new problems....
For those that haven't seen it, the best reference for Postgresql and SQL (IMHO!) is
PostgreSQL -- Introduction and Concepts by Bruce Momjian
Soon to be published, it's available online at:
http://www.postgresql.org/docs/awbook.html
-Bob