*** Check that the parts are sorted according to the new key. ***
1	2	0	10
1	2	0	20
1	2	2	40
1	2	2	50
1	2	1	30
*** Check that the rows are collapsed according to the new key. ***
1	2	0	30
1	2	1	30
1	2	4	90
*** Check SHOW CREATE TABLE ***
CREATE TABLE test.summing ( x UInt32,  y UInt32,  z UInt32,  val UInt32) ENGINE = SummingMergeTree PRIMARY KEY (x, y) ORDER BY (x, y, -z) SETTINGS index_granularity = 8192