diff --git a/shardingsphere-infra/shardingsphere-infra-common/src/main/java/org/apache/shardingsphere/infra/metadata/schema/model/TableMetaData.java b/shardingsphere-infra/shardingsphere-infra-common/src/main/java/org/apache/shardingsphere/infra/metadata/schema/model/TableMetaData.java
index c8d09a7285f45..8e146de8dbcb7 100644
--- a/shardingsphere-infra/shardingsphere-infra-common/src/main/java/org/apache/shardingsphere/infra/metadata/schema/model/TableMetaData.java
+++ b/shardingsphere-infra/shardingsphere-infra-common/src/main/java/org/apache/shardingsphere/infra/metadata/schema/model/TableMetaData.java
@@ -72,7 +72,7 @@ private Map<String, ColumnMetaData> getColumns(final Collection<ColumnMetaData>
                 primaryKeyColumns.add(lowerColumnName);
             }
         }
-        return Collections.synchronizedMap(result);
+        return result;
     }
     
     private Map<String, IndexMetaData> getIndexes(final Collection<IndexMetaData> indexMetaDataList) {
@@ -80,7 +80,7 @@ private Map<String, IndexMetaData> getIndexes(final Collection<IndexMetaData> in
         for (IndexMetaData each : indexMetaDataList) {
             result.put(each.getName().toLowerCase(), each);
         }
-        return Collections.synchronizedMap(result);
+        return result;
     }
     
     /**