impl

tests/queries/0_stateless/03273_group_by_in_order_still_used_when_group_by_key_doesnt_match_order_by_key.reference

@@ -0,0 +1,2 @@
+Order: a ASC, b ASC
+ReadType: InOrder

tests/queries/0_stateless/03273_group_by_in_order_still_used_when_group_by_key_doesnt_match_order_by_key.sql

@@ -0,0 +1,24 @@
+CREATE TABLE test
+(
+  a UInt64,
+  b UInt64
+)
+ENGINE = MergeTree
+ORDER BY (a, b);
+
+INSERT INTO test SELECT number, number FROM numbers_mt(1e6);
+
+set enable_analyzer = 1;
+
+SELECT trimBoth(replaceRegexpAll(explain, '__table1.', ''))
+FROM
+(
+  EXPLAIN actions = 1
+  SELECT count(*)
+  FROM test
+  GROUP BY
+      b,
+      a
+  SETTINGS optimize_aggregation_in_order = 1
+)
+WHERE explain LIKE '%Order%';