SELECT columnar_test_helpers.compression_type_supported('zstd') AS zstd_supported \gset \if :zstd_supported \else \q \endif CREATE SCHEMA am_zstd; SET search_path TO am_zstd; SET columnar.compression TO 'zstd'; CREATE TABLE test_zstd (a int, b text, c int) USING columnar; INSERT INTO test_zstd SELECT i % 1000, (i % 10)::text, 4 FROM generate_series(1, 10000) i; SELECT count(*) FROM test_zstd; INSERT INTO test_zstd SELECT floor(i / 2), floor(i / 10)::text, 5 FROM generate_series(1000, 11000) i; SELECT count(*) FROM test_zstd; CREATE TABLE test_none (LIKE test_zstd) USING columnar; INSERT INTO test_none SELECT * FROM test_zstd; SELECT DISTINCT * FROM test_zstd ORDER BY a, b, c LIMIT 5; VACUUM FULL test_zstd; SELECT pg_relation_size('test_zstd') AS size_comp_level_default \gset -- change compression level ALTER TABLE test_zstd SET (columnar.compression_level = 19); VACUUM FULL test_zstd; SELECT pg_relation_size('test_zstd') AS size_comp_level_19 \gset -- verify that higher compression level compressed better SELECT :size_comp_level_default > :size_comp_level_19 AS size_changed; -- compare compression rate to pglz SET columnar.compression TO 'pglz'; CREATE TABLE test_pglz (LIKE test_zstd) USING columnar; INSERT INTO test_pglz SELECT * FROM test_zstd; SELECT pg_relation_size('test_pglz') AS size_pglz \gset -- verify that zstd compressed better than pglz SELECT :size_pglz > :size_comp_level_default; -- Other operations ANALYZE test_zstd; SELECT count(DISTINCT test_zstd.*) FROM test_zstd; TRUNCATE test_zstd; SELECT count(DISTINCT test_zstd.*) FROM test_zstd; SET client_min_messages TO WARNING; DROP SCHEMA am_zstd CASCADE;