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https://issues.apache.org/jira/browse/FLINK-6232?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16073717#comment-16073717
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ASF GitHub Bot commented on FLINK-6232:
---------------------------------------
Github user fhueske commented on a diff in the pull request:
https://github.com/apache/flink/pull/3715#discussion_r125452889
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/runtime/join/WindowJoinUtil.scala
---
@@ -0,0 +1,361 @@
+/*
+ * 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 java.math.{BigDecimal => JBigDecimal}
+import java.util
+
+import org.apache.calcite.plan.RelOptUtil
+import org.apache.calcite.rel.`type`.RelDataType
+import org.apache.calcite.rel.core.JoinRelType
+import org.apache.calcite.rex._
+import org.apache.calcite.sql.SqlKind
+import org.apache.flink.api.common.functions.FlatJoinFunction
+import org.apache.flink.api.common.typeinfo.TypeInformation
+import org.apache.flink.table.api.{TableConfig, TableException}
+import org.apache.flink.table.calcite.FlinkTypeFactory
+import org.apache.flink.table.codegen.{CodeGenerator, ExpressionReducer}
+import org.apache.flink.table.functions.TimeMaterializationSqlFunction
+import org.apache.flink.table.plan.schema.{RowSchema,
TimeIndicatorRelDataType}
+import org.apache.flink.types.Row
+
+import scala.collection.JavaConversions._
+
+/**
+ * An util class to help analyze and build join code .
+ */
+object WindowJoinUtil {
+
+ /**
+ * Analyze time-condtion to get time boundary for each stream and get
the time type
+ * and return remain condition.
+ *
+ * @param condition join condition
+ * @param leftLogicalFieldCnt left stream logical field num
+ * @param leftPhysicalFieldCnt left stream physical field num
+ * @param inputType left and right connect stream type
+ * @param rexBuilder util to build rexNode
+ * @param config table environment config
+ * @return timetype, left lower boundary, right lower boundary, remain
condition
+ */
+ private[flink] def analyzeTimeBoundary(
+ condition: RexNode,
+ leftLogicalFieldCnt: Int,
+ leftPhysicalFieldCnt: Int,
+ inputType: RelDataType,
+ rexBuilder: RexBuilder,
+ config: TableConfig): (RelDataType, Long, Long, Option[RexNode]) = {
+
+ // Converts the condition to conjunctive normal form (CNF)
+ val cnfCondition = RexUtil.toCnf(rexBuilder, condition)
+
+ // split the condition into time indicator condition and other
condition
+ val (timeTerms, remainTerms) =
+ splitJoinCondition(
+ cnfCondition,
+ leftLogicalFieldCnt,
+ inputType
+ )
+
+ if (timeTerms.size != 2) {
+ throw new TableException("A time-based stream join requires exactly
" +
+ "two join predicates that bound the time in both directions.")
+ }
+
+ // extract time offset from the time indicator conditon
+ val streamTimeOffsets =
+ timeTerms.map(x => extractTimeOffsetFromCondition(x._3, x._2,
rexBuilder, config))
+
+ val (leftLowerBound, leftUpperBound) =
+ streamTimeOffsets match {
+ case Seq((x, true), (y, false)) => (x, y)
+ case Seq((x, false), (y, true)) => (y, x)
+ case _ =>
+ throw new TableException(
+ "Time-based join conditions must reference the time attribute
of both input tables.")
+ }
+
+ // compose the remain condition list into one condition
+ val remainCondition =
+ remainTerms match {
+ case Seq() => None
+ case _ =>
+ // turn the logical field index to physical field index
+ def transInputRef(expr: RexNode): RexNode = {
+ expr match {
+ case c: RexCall =>
+ val newOps = c.operands.map(transInputRef(_))
+ rexBuilder.makeCall(c.getType, c.getOperator, newOps)
+ case i: RexInputRef if i.getIndex >= leftLogicalFieldCnt =>
+ rexBuilder.makeInputRef(
+ i.getType,
+ i.getIndex - leftLogicalFieldCnt + leftPhysicalFieldCnt)
+ case _ => expr
+ }
+ }
+
+ Some(remainTerms.map(transInputRef(_)).reduceLeft( (l, r) => {
+ RelOptUtil.andJoinFilters(rexBuilder, l, r)
+ }))
+ }
+
+ (timeTerms.get(0)._1, leftLowerBound, leftUpperBound, remainCondition)
+ }
+
+ /**
+ * Split the join conditions into time condition and non-time condition
+ *
+ * @return (Seq(timeTerms), Seq(remainTerms)),
+ */
+ private def splitJoinCondition(
--- End diff --
I think we can simplify this method a bit more by removing the recursive
call.
We could do a first check if the `cnfCondition` is of `SqlKind.AND` and
throw an exception if this is not the case (it is in CNF and we need at least
two predicates for the bounds).
If it is an AND, we simply iterate over the operands of `AND`.
> Support proctime inner equi-join between two streams in the SQL API
> -------------------------------------------------------------------
>
> Key: FLINK-6232
> URL: https://issues.apache.org/jira/browse/FLINK-6232
> Project: Flink
> Issue Type: Sub-task
> Components: Table API & SQL
> Reporter: hongyuhong
> Assignee: hongyuhong
>
> The goal of this issue is to add support for inner equi-join on proc time
> streams to the SQL interface.
> Queries similar to the following should be supported:
> {code}
> SELECT o.proctime, o.productId, o.orderId, s.proctime AS shipTime
> FROM Orders AS o
> JOIN Shipments AS s
> ON o.orderId = s.orderId
> AND o.proctime BETWEEN s.proctime AND s.proctime + INTERVAL '1' HOUR;
> {code}
> The following restrictions should initially apply:
> * The join hint only support inner join
> * The ON clause should include equi-join condition
> * The time-condition {{o.proctime BETWEEN s.proctime AND s.proctime +
> INTERVAL '1' HOUR}} only can use proctime that is a system attribute, the
> time condition only support bounded time range like {{o.proctime BETWEEN
> s.proctime - INTERVAL '1' HOUR AND s.proctime + INTERVAL '1' HOUR}}, not
> support unbounded like {{o.proctime > s.protime}}, and should include both
> two stream's proctime attribute, {{o.proctime between proctime() and
> proctime() + 1}} should also not be supported.
> This issue includes:
> * Design of the DataStream operator to deal with stream join
> * Translation from Calcite's RelNode representation (LogicalJoin).
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