[feature](agg) add the aggregation function 'mag_agg' (#22043)

New aggregation function: map_agg.

This function requires two arguments: a key and a value, which are used to build a map.

select map_agg(column1, column2) from t group by column3;

be/src/vec/aggregate_functions/aggregate_function_map.cpp

@@ -0,0 +1,68 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#include "vec/aggregate_functions/aggregate_function_map.h"
+
+#include "runtime/primitive_type.h"
+#include "vec/aggregate_functions/helpers.h"
+
+namespace doris::vectorized {
+
+template <typename K>
+AggregateFunctionPtr create_agg_function_map_agg(const DataTypes& argument_types,
+                                                 const bool result_is_nullable) {
+    return creator_without_type::create_ignore_nullable<
+            AggregateFunctionMapAgg<AggregateFunctionMapAggData<K>, K>>(argument_types,
+                                                                        result_is_nullable);
+}
+
+AggregateFunctionPtr create_aggregate_function_map_agg(const std::string& name,
+                                                       const DataTypes& argument_types,
+                                                       const bool result_is_nullable) {
+    WhichDataType type(remove_nullable(argument_types[0]));
+
+#define DISPATCH(TYPE)               \
+    if (type.idx == TypeIndex::TYPE) \
+        return create_agg_function_map_agg<TYPE>(argument_types, result_is_nullable);
+
+    FOR_NUMERIC_TYPES(DISPATCH)
+    FOR_DECIMAL_TYPES(DISPATCH)
+#undef DISPATCH
+
+    if (type.idx == TypeIndex::String) {
+        return create_agg_function_map_agg<String>(argument_types, result_is_nullable);
+    }
+    if (type.idx == TypeIndex::DateTime || type.idx == TypeIndex::Date) {
+        return create_agg_function_map_agg<Int64>(argument_types, result_is_nullable);
+    }
+    if (type.idx == TypeIndex::DateV2) {
+        return create_agg_function_map_agg<UInt32>(argument_types, result_is_nullable);
+    }
+    if (type.idx == TypeIndex::DateTimeV2) {
+        return create_agg_function_map_agg<UInt64>(argument_types, result_is_nullable);
+    }
+
+    LOG(WARNING) << fmt::format("unsupported input type {} for aggregate function {}",
+                                argument_types[0]->get_name(), name);
+    return nullptr;
+}
+
+void register_aggregate_function_map_agg(AggregateFunctionSimpleFactory& factory) {
+    factory.register_function_both("map_agg", create_aggregate_function_map_agg);
+}
+
+} // namespace doris::vectorized