DROP TABLE IF EXISTS test.partitions; set allow_deprecated_syntax_for_merge_tree=1; CREATE TABLE test.partitions (EventDate Date, CounterID UInt32) ENGINE = MergeTree(EventDate, CounterID, 8192); INSERT INTO test.partitions SELECT EventDate + UserID % 365 AS EventDate, CounterID FROM test.hits WHERE CounterID = 1704509; SELECT count() FROM test.partitions; SELECT count() FROM test.partitions WHERE EventDate >= toDate('2015-01-01') AND EventDate < toDate('2015-02-01'); SELECT count() FROM test.partitions WHERE EventDate < toDate('2015-01-01') OR EventDate >= toDate('2015-02-01'); ALTER TABLE test.partitions DETACH PARTITION 201501; SELECT count() FROM test.partitions; SELECT count() FROM test.partitions WHERE EventDate >= toDate('2015-01-01') AND EventDate < toDate('2015-02-01'); SELECT count() FROM test.partitions WHERE EventDate < toDate('2015-01-01') OR EventDate >= toDate('2015-02-01'); ALTER TABLE test.partitions ATTACH PARTITION 201501; SELECT count() FROM test.partitions; SELECT count() FROM test.partitions WHERE EventDate >= toDate('2015-01-01') AND EventDate < toDate('2015-02-01'); SELECT count() FROM test.partitions WHERE EventDate < toDate('2015-01-01') OR EventDate >= toDate('2015-02-01'); ALTER TABLE test.partitions DETACH PARTITION 201403; SELECT count() FROM test.partitions; INSERT INTO test.partitions SELECT EventDate + UserID % 365 AS EventDate, CounterID FROM test.hits WHERE CounterID = 1704509 AND toStartOfMonth(EventDate) = toDate('2014-03-01'); SELECT count() FROM test.partitions; ALTER TABLE test.partitions ATTACH PARTITION 201403; SELECT count() FROM test.partitions; DROP TABLE test.partitions;