-- float8 check CREATE TABLE float8tmp (a float8); \copy float8tmp from 'data/float8.data' SET enable_seqscan=on; SELECT count(*) FROM float8tmp WHERE a < -1890.0; SELECT count(*) FROM float8tmp WHERE a <= -1890.0; SELECT count(*) FROM float8tmp WHERE a = -1890.0; SELECT count(*) FROM float8tmp WHERE a >= -1890.0; SELECT count(*) FROM float8tmp WHERE a > -1890.0; SELECT a, a <-> '-1890.0' FROM float8tmp ORDER BY a <-> '-1890.0' LIMIT 3; CREATE INDEX float8idx ON float8tmp USING gist ( a ); SET enable_seqscan=off; SELECT count(*) FROM float8tmp WHERE a < -1890.0::float8; SELECT count(*) FROM float8tmp WHERE a <= -1890.0::float8; SELECT count(*) FROM float8tmp WHERE a = -1890.0::float8; SELECT count(*) FROM float8tmp WHERE a >= -1890.0::float8; SELECT count(*) FROM float8tmp WHERE a > -1890.0::float8; EXPLAIN (COSTS OFF) SELECT a, a <-> '-1890.0' FROM float8tmp ORDER BY a <-> '-1890.0' LIMIT 3; SELECT a, a <-> '-1890.0' FROM float8tmp ORDER BY a <-> '-1890.0' LIMIT 3;