Github user twalthr commented on a diff in the pull request:
https://github.com/apache/flink/pull/4471#discussion_r152753104
--- 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 {
+ case _: TimeIndicatorRelDataType => true
+ case _ => false
+ }
+ case c: RexCall =>
+ c.operands.asScala.exists(accessesTimeAttribute(_, inputType))
+ case _ => false
+ }
+ }
+
+ override def matches(call: RelOptRuleCall): Boolean = {
+ val join: FlinkLogicalJoin = call.rel(0).asInstanceOf[FlinkLogicalJoin]
+ val joinInfo = join.analyzeCondition
+
+ val (windowBounds, remainingPreds) =
WindowJoinUtil.extractWindowBoundsFromPredicate(
+ joinInfo.getRemaining(join.getCluster.getRexBuilder),
+ join.getLeft.getRowType.getFieldCount,
+ join.getRowType,
+ join.getCluster.getRexBuilder,
+ TableConfig.DEFAULT)
+
+ // remaining predicate must not access time attributes
+ val remainingPredsAccessTime = remainingPreds.isDefined &&
+ accessesTimeAttribute(remainingPreds.get, join.getRowType)
+
+ !windowBounds.isDefined && !remainingPredsAccessTime
--- End diff --
Replace with `windowBounds.isEmpty`
---
