create unique index tbl_iname_idx on tbl (lower(name_field))
By the way, in case it wasn't obvious, this has a nice side-benefit. Namely, PG will use that index for caseless lookups, so you can do this:
select * from tbl where lower(name_field) = lower('John'); very efficiently. - John D. Burger MITRE ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings