Convert function with setting to cluster function

Author: ianton-ru

src/Storages/ObjectStorage/StorageObjectStorageCluster.cpp

@@ -269,18 +269,53 @@ void StorageObjectStorageCluster::updateQueryToSendIfNeeded(
     {
         configuration->addStructureAndFormatToArgsIfNeeded(args, structure, configuration->format, context, /*with_structure=*/true);
 
+        /// Convert to old-stype *Cluster table function.
+        /// This allows to use old clickhouse versions in cluster.
+        static std::unordered_map<std::string, std::string> function_to_cluster_function = {
+            {"s3", "s3Cluster"},
+            {"azureBlobStorage", "azureBlobStorageCluster"},
+            {"hdfs", "hdfsCluster"},
+            {"iceberg", "icebergS3Cluster"},
+            {"icebergS3", "icebergS3Cluster"},
+            {"icebergAzure", "icebergAzureCluster"},
+            {"icebergHDFS", "icebergHDFSCluster"},
+            {"deltaLake", "deltaLakeCluster"},
+            {"hudi", "hudiCluster"},
+        };
+
+        ASTFunction * table_function = extractTableFunctionFromSelectQuery(query);
+
+        auto p = function_to_cluster_function.find(table_function->name);
+        if (p == function_to_cluster_function.end())
+        {
+            throw Exception(
+                ErrorCodes::LOGICAL_ERROR,
+                "Can't find cluster name for table function {}",
+                table_function->name);
+        }
+
+        table_function->name = p->second;
+
+        auto cluster_name = getClusterName(context);
+        auto cluster_name_arg = std::make_shared<ASTLiteral>(cluster_name);
+        args.insert(args.begin(), cluster_name_arg);
+
         auto * select_query = query->as<ASTSelectQuery>();
-        if (select_query)
+        if (!select_query)
+            throw Exception(
+                ErrorCodes::LOGICAL_ERROR,
+                "Expected SELECT query from table function {}",
+                configuration->getEngineName());
+
+        auto settings = select_query->settings();
+        if (settings)
         {
-            auto settings = select_query->settings();
-            if (settings)
+            auto & settings_ast = settings->as<ASTSetQuery &>();
+            if (settings_ast.changes.removeSetting("object_storage_cluster") && settings_ast.changes.empty())
             {
-                auto & settings_ast = settings->as<ASTSetQuery &>();
-                if (settings_ast.changes.removeSetting("object_storage_cluster") && settings_ast.changes.empty())
-                {
-                    select_query->setExpression(ASTSelectQuery::Expression::SETTINGS, {});
-                }
+                select_query->setExpression(ASTSelectQuery::Expression::SETTINGS, {});
             }
+            /// No throw if not found - `object_storage_cluster` can be global setting.
         }
     }
     else

src/Storages/extractTableFunctionArgumentsFromSelectQuery.cpp

@@ -11,7 +11,7 @@
 namespace DB
 {
 
-ASTExpressionList * extractTableFunctionArgumentsFromSelectQuery(ASTPtr & query)
+ASTFunction * extractTableFunctionFromSelectQuery(ASTPtr & query)
 {
     auto * select_query = query->as<ASTSelectQuery>();
     if (!select_query || !select_query->tables())
@@ -23,6 +23,14 @@ ASTExpressionList * extractTableFunctionArgumentsFromSelectQuery(ASTPtr & query)
         return nullptr;
 
     auto * table_function = table_expression->table_function->as<ASTFunction>();
+    return table_function;
+}
+
+ASTExpressionList * extractTableFunctionArgumentsFromSelectQuery(ASTPtr & query)
+{
+    auto * table_function = extractTableFunctionFromSelectQuery(query);
+    if (!table_function)
+        return nullptr;
     return table_function->arguments->as<ASTExpressionList>();
 }
 

src/Storages/extractTableFunctionArgumentsFromSelectQuery.h

@@ -1,11 +1,13 @@
 #pragma once
 
 #include <Parsers/IAST_fwd.h>
+#include <Parsers/ASTFunction.h>
 #include <Parsers/ASTExpressionList.h>
 
 namespace DB
 {
 
+ASTFunction * extractTableFunctionFromSelectQuery(ASTPtr & query);
 ASTExpressionList * extractTableFunctionArgumentsFromSelectQuery(ASTPtr & query);
 
 }