set enable_seqscan=off; CREATE TABLE test_oid ( i oid ); INSERT INTO test_oid VALUES (0),(1),(2),(3),(4),(5); CREATE INDEX idx_oid ON test_oid USING rum (i); SELECT * FROM test_oid WHERE i<3::oid ORDER BY i; i --- 0 1 2 (3 rows) SELECT * FROM test_oid WHERE i<=3::oid ORDER BY i; i --- 0 1 2 3 (4 rows) SELECT * FROM test_oid WHERE i=3::oid ORDER BY i; i --- 3 (1 row) SELECT * FROM test_oid WHERE i>=3::oid ORDER BY i; i --- 3 4 5 (3 rows) SELECT * FROM test_oid WHERE i>3::oid ORDER BY i; i --- 4 5 (2 rows)