SET enable_seqscan = off; CREATE TABLE t (val bit(3)); INSERT INTO t (val) VALUES (B'000'), (B'100'), (B'111'), (NULL); CREATE INDEX ON t USING hnsw (val bit_hamming_ops); INSERT INTO t (val) VALUES (B'110'); SELECT * FROM t ORDER BY val <~> B'111'; SELECT COUNT(*) FROM (SELECT * FROM t ORDER BY val <~> (SELECT NULL::bit)) t2; DROP TABLE t; -- TODO move CREATE TABLE t (val varbit(3)); CREATE INDEX ON t USING hnsw (val bit_hamming_ops); CREATE INDEX ON t USING hnsw ((val::bit(3)) bit_hamming_ops); DROP TABLE t;