Add failing test for replicated materialized views with union

Added a test to reproduce issue where INSERTs to a materalized view
with UNIONs fails on a replica where the materialized view was not created

Author: samay-sharma

tests/integration/test_matview_union_replicated/test.py

@@ -0,0 +1,86 @@
+import pytest
+from helpers.cluster import ClickHouseCluster
+from helpers.test_tools import assert_eq_with_retry
+
+cluster = ClickHouseCluster(__file__)
+
+# Create two nodes - one main node and one replica
+node1 = cluster.add_instance("node1", with_zookeeper=True)
+node2 = cluster.add_instance("node2", with_zookeeper=True)
+
+@pytest.fixture(scope="module")
+def started_cluster():
+    try:
+        cluster.start()
+        yield cluster
+    finally:
+        cluster.shutdown()
+
+def test_matview_union_replicated(started_cluster):
+
+    # Create replicated database, source and target tables and matview
+    node1.query("DROP DATABASE IF EXISTS union_test_replicated SYNC")
+    node1.query("CREATE DATABASE union_test_replicated ENGINE=Replicated('/test/union_replica' , 'shard1', 'replica' || '1');")
+
+    node1.query("""
+    CREATE TABLE union_test_replicated.source_1
+    (
+        timestamp DateTime,
+        value Float64
+    )
+    ENGINE = ReplicatedMergeTree
+    ORDER BY timestamp
+    """)
+
+    node1.query("""
+    CREATE TABLE union_test_replicated.source_2
+    (
+        timestamp DateTime,
+        value Float64
+    )
+    ENGINE = ReplicatedMergeTree
+    ORDER BY timestamp
+    """)
+
+    node1.query("""
+    CREATE TABLE union_test_replicated.target
+    (
+        timestamp DateTime,
+        value Float64
+    )
+    ENGINE = ReplicatedMergeTree
+    ORDER BY timestamp
+    """)
+    
+    node1.query("""
+    CREATE MATERIALIZED VIEW union_test_replicated.mv_test TO union_test_replicated.target AS
+    WITH source_data AS
+    (
+        SELECT timestamp, value FROM union_test_replicated.source_1
+        UNION ALL
+        SELECT timestamp, value FROM union_test_replicated.source_2
+    )
+    SELECT timestamp, value FROM source_data
+    """)
+
+    # Verify INSERT works on Node #1
+    node1.query("INSERT INTO union_test_replicated.source_1 VALUES (now(), 1)")
+
+    # Attach replica on second node
+    node2.query("DROP DATABASE IF EXISTS union_test_replicated SYNC")
+    node2.query("CREATE DATABASE union_test_replicated ENGINE=Replicated('/test/union_replica' , 'shard1', 'replica' || '2');")
+    node2.query("SYSTEM SYNC DATABASE REPLICA union_test_replicated")
+
+    # Verify the table structure on replica
+    assert_eq_with_retry(
+        node2,
+        "DESCRIBE TABLE union_test_replicated.source_1",
+        "timestamp\tDateTime\t\t\t\t\nvalue\tFloat64\t\t\t\t\n"
+    )
+
+    # Run INSERT on replica
+    node2.query("INSERT INTO union_test_replicated.source_1 VALUES (now(), 1)")
+
+    # Clean up
+    node1.query("DROP DATABASE IF EXISTS union_test_replicated SYNC")
+    node2.query("DROP DATABASE IF EXISTS union_test_replicated SYNC")