Github user twalthr commented on a diff in the pull request:
https://github.com/apache/flink/pull/4471#discussion_r152745910
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/plan/rules/datastream/DataStreamJoinRule.scala
---
@@ -0,0 +1,108 @@
+/*
+ * 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.plan.rules.datastream
+
+import org.apache.calcite.plan.{RelOptRule, RelOptRuleCall, RelTraitSet}
+import org.apache.calcite.rel.RelNode
+import org.apache.calcite.rel.`type`.RelDataType
+import org.apache.calcite.rel.convert.ConverterRule
+import org.apache.calcite.rex.{RexCall, RexInputRef, RexNode}
+import org.apache.flink.table.api.TableConfig
+import org.apache.flink.table.plan.nodes.FlinkConventions
+import org.apache.flink.table.plan.nodes.datastream.DataStreamJoin
+import org.apache.flink.table.plan.nodes.logical.FlinkLogicalJoin
+import org.apache.flink.table.plan.schema.{RowSchema,
TimeIndicatorRelDataType}
+import org.apache.flink.table.runtime.join.WindowJoinUtil
+
+import scala.collection.JavaConverters._
+
+class DataStreamJoinRule
+ extends ConverterRule(
+ classOf[FlinkLogicalJoin],
+ FlinkConventions.LOGICAL,
+ FlinkConventions.DATASTREAM,
+ "DataStreamJoinRule") {
+
+ /**
+ * Checks if an expression accesses a time attribute.
+ *
+ * @param expr The expression to check.
+ * @param inputType The input type of the expression.
+ * @return True, if the expression accesses a time attribute. False
otherwise.
+ */
+ def accessesTimeAttribute(expr: RexNode, inputType: RelDataType):
Boolean = {
+ expr match {
+ case i: RexInputRef =>
+ val accessedType = inputType.getFieldList.get(i.getIndex).getType
+ accessedType match {
--- End diff --
Use `FlinkTypeFactory.isTimeIndicatorType`
---
