I have a table with an array column. I added a GIN index to the array: CREATE INDEX foo_idx ON t USING GIN (alternatecodes) WHERE alternatecodes IS NOT NULL; That's all well and good. However, some queries started failing and I was able to reproduce the behavior in psql! SELECT * FROM t WHERE alternatecodes IS NOT NULL; returns: ERROR: GIN indexes do not support whole-index scans Whaaa? Adding an *index* makes my /queries/ stop working? How can this be? This really violated my principle of least surprise. If GIN indexes don't support whole-index scans, fine, don't use them, but don't make a perfectly valid query fail because of it. This seems like a bug. Is it? PostgreSQL version: PostgreSQL 8.4.5 on x86_64-redhat-linux-gnu, compiled by GCC gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-48), 64-bit -- Jon -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance