[GitHub] [hive] jcamachor commented on a change in pull request #866: HIVE-22536 Improve return path enabling/disabling

[GitBox <gi...@apache.org>]

jcamachor commented on a change in pull request #866: HIVE-22536 Improve return path enabling/disabling
URL: https://github.com/apache/hive/pull/866#discussion_r357501690
 
 

 ##########
 File path: ql/src/java/org/apache/hadoop/hive/ql/parse/ReturnPathManager.java
 ##########
 @@ -0,0 +1,61 @@
+/*
+ * 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.
+ */
+
+package org.apache.hadoop.hive.ql.parse;
+
+import org.apache.hadoop.hive.conf.HiveConf;
+
+/**
+ * This is a temporary class for the time while we are in transition to use return path only.
+ * It's purpose is to decide if Hive should use return path.
+ */
+public final class ReturnPathManager {
+  private ReturnPathManager() {
+    throw new UnsupportedOperationException("ReturnPathManager should not be instantiated");
+  }
+
+  private static ThreadLocal<Boolean> useReturnPath = new ThreadLocal<>();
+
+  public static void init(HiveConf conf, ASTNode root) {
+    boolean use = shouldUseReturnPath(conf, root);
+    useReturnPath.set(use);
+  }
+
+  public static boolean shouldUse() {
+    return useReturnPath.get();
+  }
+
+  private static boolean shouldUseReturnPath(HiveConf conf, ASTNode root) {
 
 Review comment:
   I believe it is better to make this decision in terms of `RelNode` plan rather than `ASTNode` since the optimizer may introduce some arbitrary complex operators and expressions. You can implement a custom `RelVisitorImpl` that traverses the tree and returns whether any operator/expression is supported or not. The visitor would be executed before the block that applies the rules to aid in translation from Calcite tree to Hive tree. I also think we can potentially revisit the decision on checking that return path boolean when we create the HiveTableScan operator.

----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
 
For queries about this service, please contact Infrastructure at:
users@infra.apache.org


With regards,
Apache Git Services

---------------------------------------------------------------------
To unsubscribe, e-mail: gitbox-unsubscribe@hive.apache.org
For additional commands, e-mail: gitbox-help@hive.apache.org