Github user walterddr commented on a diff in the pull request:
https://github.com/apache/flink/pull/5327#discussion_r172408402
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/runtime/join/NonWindowLeftJoinWithNonEquiPredicates.scala
---
@@ -0,0 +1,228 @@
+/*
+ * 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.flink.table.runtime.join
+
+import org.apache.flink.api.common.state._
+import org.apache.flink.api.common.typeinfo.TypeInformation
+import org.apache.flink.api.java.tuple.{Tuple2 => JTuple2}
+import org.apache.flink.configuration.Configuration
+import org.apache.flink.streaming.api.functions.co.CoProcessFunction
+import org.apache.flink.table.api.{StreamQueryConfig, Types}
+import org.apache.flink.table.runtime.types.CRow
+import org.apache.flink.types.Row
+import org.apache.flink.util.Collector
+
+/**
+ * Connect data for left stream and right stream. Only use for LeftJoin
with NonEquiPredicates.
+ * An MapState of type [Row, Long] is added to record how many rows from
the right table can be
+ * matched for each left row. Left join without NonEquiPredicates doesn't
need it because
+ * left rows can always join right rows as long as join keys are same.
+ *
+ * @param leftType the input type of left stream
+ * @param rightType the input type of right stream
+ * @param resultType the output type of join
+ * @param genJoinFuncName the function code of other non-equi condition
+ * @param genJoinFuncCode the function name of other non-equi condition
+ * @param queryConfig the configuration for the query to generate
+ */
+class NonWindowLeftJoinWithNonEquiPredicates(
+ leftType: TypeInformation[Row],
+ rightType: TypeInformation[Row],
+ resultType: TypeInformation[CRow],
+ genJoinFuncName: String,
+ genJoinFuncCode: String,
+ queryConfig: StreamQueryConfig)
+ extends NonWindowJoin(
+ leftType,
+ rightType,
+ resultType,
+ genJoinFuncName,
+ genJoinFuncCode,
+ queryConfig) {
+
+ // result row, all field from right will be null
+ private var resultRow: Row = _
+ // how many matched rows from the right table for each left row
+ private var leftJoinCnt: MapState[Row, Long] = _
+
+ override def open(parameters: Configuration): Unit = {
+ super.open(parameters)
+
+ val leftJoinCntDescriptor = new MapStateDescriptor[Row, Long](
--- End diff --
I think either is fine as long as they are consistent.
---
