\set ECHO all \timing DROP TABLE perftest; CREATE TABLE perftest (col text); -- prime table with one row INSERT INTO perftest VALUES ('0.364461265208414'); -- continously double the table size INSERT INTO perftest SELECT random()::text FROM perftest; INSERT INTO perftest SELECT random()::text FROM perftest; INSERT INTO perftest SELECT random()::text FROM perftest; INSERT INTO perftest SELECT random()::text FROM perftest; INSERT INTO perftest SELECT random()::text FROM perftest; INSERT INTO perftest SELECT random()::text FROM perftest; INSERT INTO perftest SELECT random()::text FROM perftest; INSERT INTO perftest SELECT random()::text FROM perftest; INSERT INTO perftest SELECT random()::text FROM perftest; INSERT INTO perftest SELECT random()::text FROM perftest; INSERT INTO perftest SELECT random()::text FROM perftest; INSERT INTO perftest SELECT random()::text FROM perftest; INSERT INTO perftest SELECT random()::text FROM perftest; INSERT INTO perftest SELECT random()::text FROM perftest; -- insert a constant in the middle of the table, for use later INSERT INTO perftest VALUES ('0.608254158221304'); INSERT INTO perftest SELECT random()::text FROM perftest; -- 32770 rows -- vacuum, create index VACUUM ANALYZE perftest; CREATE INDEX i_perftest ON perftest (col); -- reduce chance of checkpoint during tests CHECKPOINT; -- turn on logging SET log_duration = TRUE; SET client_min_messages = 'log'; -- run normal and prepared queries SELECT col FROM perftest WHERE col = '0.608254158221304'; SELECT col FROM perftest WHERE col = '0.608254158221304'; SELECT col FROM perftest WHERE col = '0.608254158221304'; SELECT col FROM perftest WHERE col = '0.608254158221304'; SELECT col FROM perftest WHERE col = '0.608254158221304'; PREPARE perftest_prep (text) AS SELECT col FROM perftest WHERE col = $1; EXECUTE perftest_prep ('0.608254158221304'); EXECUTE perftest_prep ('0.608254158221304'); EXECUTE perftest_prep ('0.608254158221304'); EXECUTE perftest_prep ('0.608254158221304'); EXECUTE perftest_prep ('0.608254158221304'); -- first time the entire statement SET log_statement_stats = TRUE; -- run normal and prepared queries SELECT col FROM perftest WHERE col = '0.608254158221304'; SELECT col FROM perftest WHERE col = '0.608254158221304'; SELECT col FROM perftest WHERE col = '0.608254158221304'; SELECT col FROM perftest WHERE col = '0.608254158221304'; SELECT col FROM perftest WHERE col = '0.608254158221304'; PREPARE perftest_prep (text) AS SELECT col FROM perftest WHERE col = $1; EXECUTE perftest_prep ('0.608254158221304'); EXECUTE perftest_prep ('0.608254158221304'); EXECUTE perftest_prep ('0.608254158221304'); EXECUTE perftest_prep ('0.608254158221304'); EXECUTE perftest_prep ('0.608254158221304'); -- now log each query stage SET log_statement_stats = FALSE; SET log_parser_stats = TRUE; SET log_planner_stats = TRUE; SET log_executor_stats = TRUE; -- run normal and prepared queries SELECT col FROM perftest WHERE col = '0.608254158221304'; SELECT col FROM perftest WHERE col = '0.608254158221304'; SELECT col FROM perftest WHERE col = '0.608254158221304'; SELECT col FROM perftest WHERE col = '0.608254158221304'; SELECT col FROM perftest WHERE col = '0.608254158221304'; EXECUTE perftest_prep ('0.608254158221304'); EXECUTE perftest_prep ('0.608254158221304'); EXECUTE perftest_prep ('0.608254158221304'); EXECUTE perftest_prep ('0.608254158221304'); EXECUTE perftest_prep ('0.608254158221304');