Merge pull request #58068 from zhongyuankai/limit_materialized_view_size

A limit on the number of materialized views attached to a table.

docs/en/operations/server-configuration-parameters/settings.md

@@ -2866,3 +2866,10 @@ This also allows a mix of resolver types can be used.
 ### disable_tunneling_for_https_requests_over_http_proxy {#disable_tunneling_for_https_requests_over_http_proxy}
 
 By default, tunneling (i.e, `HTTP CONNECT`) is used to make `HTTPS` requests over `HTTP` proxy. This setting can be used to disable it.
+
+## max_materialized_views_count_for_table {#max_materialized_views_count_for_table}
+
+A limit on the number of materialized views attached to a table.
+Note that only directly dependent views are considered here, and the creation of one view on top of another view is not considered.
+
+Default value: `0`.

src/Common/ErrorCodes.cpp

@@ -591,6 +591,7 @@
     M(709, CANNOT_GET_REPLICATED_DATABASE_SNAPSHOT) \
     M(710, FAULT_INJECTED) \
     M(711, FILECACHE_ACCESS_DENIED) \
+    M(712, TOO_MANY_MATERIALIZED_VIEWS) \
     \
     M(999, KEEPER_EXCEPTION) \
     M(1000, POCO_EXCEPTION) \

src/Core/ServerSettings.h

@@ -113,6 +113,7 @@ namespace DB
     M(UInt64, total_memory_profiler_sample_max_allocation_size, 0, "Collect random allocations of size less or equal than specified value with probability equal to `total_memory_profiler_sample_probability`. 0 means disabled. You may want to set 'max_untracked_memory' to 0 to make this threshold to work as expected.", 0) \
     M(Bool, validate_tcp_client_information, false, "Validate client_information in the query packet over the native TCP protocol.", 0) \
     M(Bool, storage_metadata_write_full_object_key, false, "Write disk metadata files with VERSION_FULL_OBJECT_KEY format", 0) \
+    M(UInt64, max_materialized_views_count_for_table, 0, "A limit on the number of materialized views attached to a table.", 0) \
 
     /// If you add a setting which can be updated at runtime, please update 'changeable_settings' map in StorageSystemServerSettings.cpp
 

src/Storages/StorageMaterializedView.cpp

@@ -21,6 +21,7 @@
 
 #include <Common/typeid_cast.h>
 #include <Common/checkStackSize.h>
+#include <Core/ServerSettings.h>
 #include <QueryPipeline/Pipe.h>
 #include <Processors/QueryPlan/QueryPlan.h>
 #include <Processors/QueryPlan/ExpressionStep.h>
@@ -38,6 +39,7 @@ namespace ErrorCodes
     extern const int BAD_ARGUMENTS;
     extern const int NOT_IMPLEMENTED;
     extern const int INCORRECT_QUERY;
+    extern const int TOO_MANY_MATERIALIZED_VIEWS;
 }
 
 namespace ActionLocks
@@ -87,6 +89,16 @@ StorageMaterializedView::StorageMaterializedView(
                         "either ENGINE or an existing table in a TO clause");
 
     auto select = SelectQueryDescription::getSelectQueryFromASTForMatView(query.select->clone(), query.refresh_strategy != nullptr, local_context);
+    if (select.select_table_id)
+    {
+        auto select_table_dependent_views = DatabaseCatalog::instance().getDependentViews(select.select_table_id);
+
+        auto max_materialized_views_count_for_table = getContext()->getServerSettings().max_materialized_views_count_for_table;
+        if (max_materialized_views_count_for_table && select_table_dependent_views.size() >= max_materialized_views_count_for_table)
+            throw Exception(ErrorCodes::TOO_MANY_MATERIALIZED_VIEWS,
+                            "Too many materialized views, maximum: {}", max_materialized_views_count_for_table);
+    }
+
     storage_metadata.setSelectQuery(select);
     if (!comment.empty())
         storage_metadata.setComment(comment);

tests/integration/test_limit_materialized_view_count/configs/max_num_limit.xml

@@ -0,0 +1,3 @@
+<clickhouse>
+    <max_materialized_views_count_for_table>1</max_materialized_views_count_for_table>
+</clickhouse>

tests/integration/test_limit_materialized_view_count/test.py

@@ -0,0 +1,49 @@
+import pytest
+from helpers.cluster import ClickHouseCluster
+
+cluster = ClickHouseCluster(__file__)
+
+node = cluster.add_instance(
+    "node",
+    main_configs=["configs/max_num_limit.xml"],
+    stay_alive=True,
+)
+
+config = """<clickhouse>
+    <max_materialized_views_count_for_table>2</max_materialized_views_count_for_table>
+</clickhouse>
+"""
+
+
+@pytest.fixture(scope="module")
+def started_cluster():
+    try:
+        cluster.start()
+        for _, node in cluster.instances.items():
+            node.query(
+                f"""
+                CREATE TABLE test_tb (a String) ENGINE = MergeTree ORDER BY a;
+                """
+            )
+        yield cluster
+    finally:
+        cluster.shutdown()
+
+
+def test_limit_materialized_view_count(started_cluster):
+    node.query(
+        "CREATE MATERIALIZED VIEW test_view1 ENGINE = MergeTree ORDER BY a AS SELECT * FROM test_tb;"
+    )
+    assert "Too many materialized views" in node.query_and_get_error(
+        "CREATE MATERIALIZED VIEW test_view2 ENGINE = MergeTree ORDER BY a AS SELECT * FROM test_tb;"
+    )
+
+    node.replace_config("/etc/clickhouse-server/config.d/max_num_limit.xml", config)
+    node.restart_clickhouse()
+
+    node.query(
+        "CREATE MATERIALIZED VIEW test_view2 ENGINE = MergeTree ORDER BY a AS SELECT * FROM test_tb;"
+    )
+    assert "Too many materialized views" in node.query_and_get_error(
+        "CREATE MATERIALIZED VIEW test_view3 ENGINE = MergeTree ORDER BY a AS SELECT * FROM test_tb;"
+    )