-- Tags: no-s3-storage -- { echo } DROP TABLE IF EXISTS in_memory; CREATE TABLE in_memory (a UInt32) ENGINE = MergeTree ORDER BY a SETTINGS min_rows_for_compact_part = 1000, min_bytes_for_wide_part = 10485760; INSERT INTO in_memory VALUES (1); INSERT INTO in_memory VALUES (2); SELECT name, active, part_type FROM system.parts WHERE database = currentDatabase() AND table = 'in_memory'; SELECT * FROM in_memory ORDER BY a; -- no WAL remove since parts are still in use DETACH TABLE in_memory; ATTACH TABLE in_memory; SELECT name, active, part_type FROM system.parts WHERE database = currentDatabase() AND table = 'in_memory'; SELECT * FROM in_memory ORDER BY a; -- WAL should be removed, since on disk part covers all parts in WAL OPTIMIZE TABLE in_memory; DETACH TABLE in_memory; ATTACH TABLE in_memory; SELECT name, active, part_type FROM system.parts WHERE database = currentDatabase() AND table = 'in_memory'; -- check that the WAL will be reinitialized after remove INSERT INTO in_memory VALUES (3); DETACH TABLE in_memory; ATTACH TABLE in_memory; SELECT * FROM in_memory ORDER BY a;