Github user zuyu commented on a diff in the pull request:
https://github.com/apache/incubator-quickstep/pull/325#discussion_r153019995
--- Diff: transaction/CompatibilityChecker.hpp ---
@@ -0,0 +1,106 @@
+/**
+ * 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.
+ **/
+
+#ifndef QUICKSTEP_TRANSACTION_TRANSACTION_COMPATIBILITY_CHECKER_HPP_
+#define QUICKSTEP_TRANSACTION_TRANSACTION_COMPATIBILITY_CHECKER_HPP_
+
+#include <utility>
+#include <vector>
+
+#include "transaction/TransactionTable.hpp"
+#include "utility/Macros.hpp"
+
+namespace quickstep {
+
+class CatalogRelation;
+
+namespace transaction {
+
+/**
+ * @brief A class that checks the compatibility of a transaction with the
+ * other running transactions.
+ */
+class CompatibilityChecker {
+ public:
+ /**
+ * @brief Constructor
+ * @param transaction_table A lookup table that stores information about
+ * all the running and waiting transactions.
+ */
+ CompatibilityChecker(TransactionTable *transaction_table) {}
--- End diff --
Add `explicit`.
---
