[fix](file-cache) change metric_value column in file_cache_statistics table to string

be/src/exec/schema_scanner/schema_file_cache_statistics.cpp

@@ -32,7 +32,7 @@ std::vector<SchemaScanner::ColumnDesc> SchemaFileCacheStatisticsScanner::_s_tbls
         {"BE_IP", TYPE_VARCHAR, sizeof(StringRef), false},
         {"CACHE_PATH", TYPE_VARCHAR, sizeof(StringRef), false},
         {"METRIC_NAME", TYPE_VARCHAR, sizeof(StringRef), false},
-        {"METRIC_VALUE", TYPE_DOUBLE, sizeof(double), false}};
+        {"METRIC_VALUE", TYPE_STRING, sizeof(StringRef), false}};
 
 SchemaFileCacheStatisticsScanner::SchemaFileCacheStatisticsScanner()
         : SchemaScanner(_s_tbls_columns, TSchemaTableType::SCH_FILE_CACHE_STATISTICS) {}

be/src/io/cache/block/block_file_cache_factory.cpp

@@ -115,6 +115,9 @@ std::vector<IFileCache::QueryFileCacheContextHolderPtr> FileCacheFactory::get_qu
 }
 
 void FileCacheFactory::get_cache_stats_block(vectorized::Block* block) {
+    if (!config::enable_file_cache) {
+        return;
+    }
     // std::shared_lock<std::shared_mutex> read_lock(_qs_ctx_map_lock);
     TBackend be = BackendOptions::get_local_backend();
     int64_t be_id = be.id;
@@ -131,17 +134,6 @@ void FileCacheFactory::get_cache_stats_block(vectorized::Block* block) {
         nullable_column->get_null_map_data().emplace_back(0);
     };
 
-    auto insert_double_value = [&](int col_index, double double_val, vectorized::Block* block) {
-        vectorized::MutableColumnPtr mutable_col_ptr;
-        mutable_col_ptr = std::move(*block->get_by_position(col_index).column).assume_mutable();
-        auto* nullable_column =
-                reinterpret_cast<vectorized::ColumnNullable*>(mutable_col_ptr.get());
-        vectorized::IColumn* col_ptr = &nullable_column->get_nested_column();
-        reinterpret_cast<vectorized::ColumnVector<vectorized::Float64>*>(col_ptr)->insert_value(
-                double_val);
-        nullable_column->get_null_map_data().emplace_back(0);
-    };
-
     auto insert_string_value = [&](int col_index, std::string str_val, vectorized::Block* block) {
         vectorized::MutableColumnPtr mutable_col_ptr;
         mutable_col_ptr = std::move(*block->get_by_position(col_index).column).assume_mutable();
@@ -160,7 +152,7 @@ void FileCacheFactory::get_cache_stats_block(vectorized::Block* block) {
             insert_string_value(1, be_ip, block);                  // be ip
             insert_string_value(2, cache->get_base_path(), block); // cache path
             insert_string_value(3, k, block);                      // metric name
-            insert_double_value(4, v, block);                      // metric value
+            insert_string_value(4, std::to_string(v), block);      // metric value
         }
     }
 }

fe/fe-core/src/main/java/org/apache/doris/catalog/SchemaTable.java

@@ -524,7 +524,7 @@ public class SchemaTable extends Table {
                                     .column("BE_IP", ScalarType.createVarchar(256))
                                     .column("CACHE_PATH", ScalarType.createVarchar(256))
                                     .column("METRIC_NAME", ScalarType.createVarchar(256))
-                                    .column("METRIC_VALUE", ScalarType.createType(PrimitiveType.DOUBLE))
+                                    .column("METRIC_VALUE", ScalarType.createStringType())
                                     .build()))
             .put("workload_group_privileges",
                     new SchemaTable(SystemIdGenerator.getNextId(), "workload_group_privileges", TableType.SCHEMA,

regression-test/suites/query_p0/system/test_file_cache_statistics.groovy

@@ -0,0 +1,24 @@
+// 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.
+
+suite("test_file_cache_statistics") {
+    // not able to test result because the file cache may not be enabled
+    // in regression test.
+    // only execute the statement to make sure it won't fail.
+    sql "select * from information_schema.file_cache_statistics"
+    sql "select * from internal.information_schema.file_cache_statistics"
+}