From: Josh Kupershmidt on
Addressing TODO item "Distinguish between unique indexes and unique
constraints in \d+" for psql, and picking up from thread:
http://archives.postgresql.org/message-id/8780.1271187360(a)sss.pgh.pa.us

Attached is a simple patch which clarifies unique constraints with
"UNIQUE CONSTRAINT" in psql's \d+ description of a table. The
appearance of unique indexes is left as-is.

== Old \d+ display ==
Indexes:
"name_uniq_constr" UNIQUE, btree (name)

== New \d+ display ==
Indexes:
"name_uniq_constr" UNIQUE CONSTRAINT, btree (name)

Josh