Merge pull request #7396 from nvartolomei/nv/mv-extra-columns

Test materialized view pushing extra columns

dbms/tests/queries/0_stateless/01019_materialized_view_select_extra_columns.reference

@@ -0,0 +1,3 @@
+0
+1
+2

dbms/tests/queries/0_stateless/01019_materialized_view_select_extra_columns.sql

@@ -0,0 +1,35 @@
+DROP TABLE IF EXISTS mv_extra_columns_dst;
+DROP TABLE IF EXISTS mv_extra_columns_src;
+DROP TABLE IF EXISTS mv_extra_columns_view;
+
+CREATE TABLE mv_extra_columns_dst (
+    v UInt64
+) ENGINE = MergeTree()
+    PARTITION BY tuple()
+    ORDER BY v;
+
+CREATE TABLE mv_extra_columns_src (
+    v1 UInt64,
+    v2 UInt64
+) ENGINE = Null;
+
+-- Extra columns are ignored when pushing to destination table.
+-- This test exists to prevent unintended changes to existing behaviour.
+--
+-- Although this behaviour might not be ideal it can be exploited for 0-downtime changes to materialized views.
+-- Step 1: Add new column to source table. Step 2: Create new view reading source column.
+-- Step 3: Swap views using `RENAME TABLE`. Step 4: Add new column to destination table as well.
+CREATE MATERIALIZED VIEW mv_extra_columns_view TO mv_extra_columns_dst
+AS SELECT
+  v1 as v,
+  v2 as v2
+FROM mv_extra_columns_src;
+
+INSERT INTO mv_extra_columns_src VALUES (0, 0), (1, 1), (2, 2);
+
+SELECT * FROM mv_extra_columns_dst ORDER by v;
+SELECT * FROM mv_extra_columns_view; -- { serverError 16 }
+
+DROP TABLE mv_extra_columns_view;
+DROP TABLE mv_extra_columns_src;
+DROP TABLE mv_extra_columns_dst;