KurtYoung commented on a change in pull request #8051: [FLINK-12018] [table-planner-blink] Add support for generating optimized logical plan for Sort and Rank URL: https://github.com/apache/flink/pull/8051#discussion_r269842446
########## File path: flink-table/flink-table-planner-blink/src/main/scala/org/apache/flink/table/plan/rules/logical/FlinkLogicalRankRule.scala ########## @@ -0,0 +1,231 @@ +/* + * 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.logical + +import org.apache.flink.table.api.TableException +import org.apache.flink.table.calcite.FlinkContext +import org.apache.flink.table.plan.nodes.calcite.{ConstantRankRange, ConstantRankRangeWithoutEnd} +import org.apache.flink.table.plan.nodes.logical.{FlinkLogicalCalc, FlinkLogicalOverWindow, FlinkLogicalRank} +import org.apache.flink.table.plan.util.FlinkRelOptUtil + +import org.apache.calcite.plan.RelOptRule.{any, operand} +import org.apache.calcite.plan.{RelOptRule, RelOptRuleCall, RelOptUtil} +import org.apache.calcite.rex.{RexProgramBuilder, RexUtil} +import org.apache.calcite.sql.{SqlKind, SqlRankFunction} + +import scala.collection.JavaConversions._ + +/** + * Planner rule that matches a [[FlinkLogicalCalc]] on a [[FlinkLogicalOverWindow]], + * and converts them into a [[FlinkLogicalRank]]. + */ +abstract class FlinkLogicalRankRuleBase + extends RelOptRule( + operand(classOf[FlinkLogicalCalc], + operand(classOf[FlinkLogicalOverWindow], any()))) { + + override def onMatch(call: RelOptRuleCall): Unit = { + val calc: FlinkLogicalCalc = call.rel(0) + val window: FlinkLogicalOverWindow = call.rel(1) + val group = window.groups.get(0) + val rankFun = group.aggCalls.get(0).getOperator.asInstanceOf[SqlRankFunction] + + // the rank function is the last field of LogicalWindow + val rankFieldIndex = window.getRowType.getFieldCount - 1 + val condition = calc.getProgram.getCondition + val predicate = calc.getProgram.expandLocalRef(condition) + + val config = calc.getCluster.getPlanner.getContext.asInstanceOf[FlinkContext].getTableConfig + val (rankRange, remainingPreds) = FlinkRelOptUtil.extractRankRange( + predicate, + rankFieldIndex, + calc.getCluster.getRexBuilder, + config) + require(rankRange.isDefined) + + val cluster = window.getCluster + val rexBuilder = cluster.getRexBuilder + + val calcProgram = calc.getProgram + val exprList = calcProgram.getProjectList.map(calcProgram.expandLocalRef) + + val inputFields = RelOptUtil.InputFinder.bits(exprList, null).toList + val outputRankFunColumn = inputFields.contains(rankFieldIndex) + + val rankRowType = if (outputRankFunColumn) { + window.getRowType + } else { + val typeBuilder = rexBuilder.getTypeFactory.builder() + window.getRowType.getFieldList.dropRight(1).foreach(typeBuilder.add) + typeBuilder.build() + } + + rankRange match { + case Some(ConstantRankRange(_, rankEnd)) if rankEnd <= 0 => + throw new TableException(s"Rank end should not less than zero, but now is $rankEnd") + case _ => // do nothing + } + + val rank = new FlinkLogicalRank( + cluster, + window.getTraitSet, + window.getInput, + rankFun, + group.keys, + group.orderKeys, + rankRange.get, + outputRankFunColumn) + + val newRel = if (RexUtil.isIdentity(exprList, rankRowType) && remainingPreds.isEmpty) { + // project is trivial and filter is empty, remove the Calc + rank + } else { + val programBuilder = RexProgramBuilder.create( + rexBuilder, + rankRowType, + calcProgram.getExprList, + calcProgram.getProjectList, + remainingPreds.orNull, + calc.getRowType, + true, // normalize + null) // simplify + + calc.copy(calc.getTraitSet, rank, programBuilder.getProgram) + } + call.transformTo(newRel) + } +} + +/** + * This rule handles RANK function and rank range with end. + */ +class FlinkLogicalRankRuleForRangeEnd extends FlinkLogicalRankRuleBase { + + override def matches(call: RelOptRuleCall): Boolean = { + val calc: FlinkLogicalCalc = call.rel(0) + val window: FlinkLogicalOverWindow = call.rel(1) + + if (window.groups.size > 1) { + // only accept one window + return false + } + + val group = window.groups.get(0) + if (group.aggCalls.size > 1) { + // only accept one agg call + return false + } + + val agg = group.aggCalls.get(0) + if (!agg.getOperator.isInstanceOf[SqlRankFunction]) { + // only accept SqlRankFunction for Rank + return false + } + + if (group.lowerBound.isUnbounded && group.upperBound.isCurrentRow) { + val condition = calc.getProgram.getCondition + if (condition != null) { + val predicate = calc.getProgram.expandLocalRef(condition) + // the rank function is the last field of FlinkLogicalOverWindow + val rankFieldIndex = window.getRowType.getFieldCount - 1 + val config = calc.getCluster.getPlanner.getContext.asInstanceOf[FlinkContext].getTableConfig + val (rankRange, remainingPreds) = FlinkRelOptUtil.extractRankRange( + predicate, + rankFieldIndex, + calc.getCluster.getRexBuilder, + config) + + rankRange match { + case Some(_: ConstantRankRangeWithoutEnd) => + throw new TableException( + "Rank end is not specified. Currently rank only support TopN, " + + "which means the rank end must be specified.") + case _ => // do nothing + } + + // remaining predicate must not access rank field attributes + val remainingPredsAccessRank = remainingPreds.isDefined && + FlinkRelOptUtil.accessesRankField(remainingPreds.get, rankFieldIndex) + + rankRange.isDefined && !remainingPredsAccessRank + } else { + false + } + } else { + false + } + } +} + +/** + * This rule only handles RANK function and constant rank range. + */ +class FlinkLogicalRankRuleForConstantRange extends FlinkLogicalRankRuleBase { Review comment: Can you give some examples to show what this rule want to capture? ---------------------------------------------------------------- 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. 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