atoomula commented on a change in pull request #1386: URL: https://github.com/apache/samza/pull/1386#discussion_r455117551
########## File path: samza-sql/src/main/java/org/apache/samza/sql/translator/MessageStreamCollector.java ########## @@ -0,0 +1,214 @@ +/* + * 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.samza.sql.translator; + +import java.io.Closeable; +import java.io.Serializable; +import java.time.Duration; +import java.util.ArrayDeque; +import java.util.Collection; +import java.util.Deque; +import java.util.function.Function; +import org.apache.samza.context.Context; +import org.apache.samza.operators.KV; +import org.apache.samza.operators.MessageStream; +import org.apache.samza.operators.OutputStream; +import org.apache.samza.operators.functions.AsyncFlatMapFunction; +import org.apache.samza.operators.functions.FilterFunction; +import org.apache.samza.operators.functions.FlatMapFunction; +import org.apache.samza.operators.functions.JoinFunction; +import org.apache.samza.operators.functions.MapFunction; +import org.apache.samza.operators.functions.SinkFunction; +import org.apache.samza.operators.functions.StreamTableJoinFunction; +import org.apache.samza.operators.windows.Window; +import org.apache.samza.operators.windows.WindowPane; +import org.apache.samza.serializers.KVSerde; +import org.apache.samza.serializers.Serde; +import org.apache.samza.sql.data.SamzaSqlRelMessage; +import org.apache.samza.table.Table; + + +/** + * Collector of Map and Filter Samza Functions to collect call stack on the top of Remote table. + * This Collector will be used by Join operator and trigger it when applying the join function post lookup. + * + * Note that this is needed because the Remote Table can not expose a proper {@code MessageStream}. + * It is a work around to minimize the amount of code changes of the current Query Translator {@link org.apache.samza.sql.translator.QueryTranslator}, + * But in an ideal world, we should use Calcite planner in conventional way we can combine function when via translation of RelNodes. Review comment: Ahh.. now I get it. If we have the following condition "(p.__key__ + 1) = pv.profileId", we cannot really solve it with calcite rule change other than changing our translator code (one of which is what you did). ---------------------------------------------------------------- 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: [email protected]
