Merge pull request ClickHouse#79164 from ClickHouse/aggreation-keys-order

Preserve aggregation keys order after filter pushdown

Author: GrigoryPervakov

src/Processors/QueryPlan/Optimizations/filterPushDown.cpp

@@ -152,6 +152,14 @@ addNewFilterStepOrThrow(QueryPlan::Node * parent_node, QueryPlan::Nodes & nodes,
     /// New filter column is the first one.
     String split_filter_column_name = split_filter.getOutputs().front()->result_name;
 
+    // If no new columns added, filter just used one of the input columns as-is and moved it to the front, move it back to keep aggregation key in order.
+    if (const auto & input = node.children.at(0)->step->getOutputHeader(); split_filter.getOutputs().size() == input.columns())
+    {
+        auto pos = input.getPositionByName(split_filter_column_name);
+        if (pos != 0)
+            std::rotate(split_filter.getOutputs().begin(), split_filter.getOutputs().begin() + 1, split_filter.getOutputs().begin() + pos + 1);
+    }
+
     node.step = std::make_unique<FilterStep>(
         node.children.at(0)->step->getOutputHeader(), std::move(split_filter), std::move(split_filter_column_name), can_remove_filter);
 

tests/queries/0_stateless/01798_having_push_down.reference

@@ -1,3 +1,5 @@
 1	1	2
 1	\N
 1	1	2
+2
+1

tests/queries/0_stateless/01798_having_push_down.sql

@@ -25,3 +25,11 @@ SELECT sum(c0 = 0), min(c0 + 1), sum(c0 + 2) FROM t_having
 GROUP BY c0 HAVING c0 = 0;
 
 DROP TABLE t_having;
+
+CREATE TABLE t_exact (c0 Bool, c1 Int) ENGINE = MergeTree() ORDER BY tuple();
+INSERT INTO TABLE t_exact (c0, c1) VALUES (FALSE, 1), (TRUE, 2);
+SELECT c1 FROM t_exact GROUP BY c1, c0 HAVING c0;
+DROP TABLE t_exact;
+
+SELECT 1 FROM remote('127.0.0.{1,1}') GROUP BY (2, materialize(3)) HAVING materialize(3) SETTINGS group_by_use_nulls = true;
+