| /* |
| * 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.hadoop.hive.ql.optimizer.calcite.rules; |
| |
| import org.apache.calcite.plan.RelOptRule; |
| import org.apache.calcite.plan.RelOptRuleCall; |
| import org.apache.calcite.rel.core.Filter; |
| import org.apache.calcite.rex.RexCall; |
| import org.apache.calcite.rex.RexNode; |
| import org.apache.calcite.rex.RexShuttle; |
| import org.apache.calcite.rex.RexUtil; |
| import org.apache.calcite.tools.RelBuilder; |
| import org.apache.calcite.tools.RelBuilderFactory; |
| import org.apache.calcite.util.ImmutableBitSet; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** |
| * Planner rule that matches a {@link Filter} expression with correlated variables, and rewrites the |
| * condition in a simpler form that is more convenient for the decorrelation logic. |
| * |
| * Uncorrelated calls below a comparison operator are turned into input references by extracting the |
| * computation in a {@link org.apache.calcite.rel.core.Project} expression. An additional projection |
| * may be added on top of the new filter to retain expression equivalence. |
| * |
| * <h3>Sub-plan before</h3> |
| * <pre> |
| * LogicalProject($f0=[true]) |
| * LogicalFilter(condition=[=($cor0.DEPTNO, +($7, 30))]) |
| * LogicalTableScan(table=[[CATALOG, SALES, EMP]]) |
| * </pre> |
| * <h3>Sub-plan after</h3> |
| * <pre> |
| * LogicalProject($f0=[true]) |
| * LogicalProject(EMPNO=[$0], ENAME=[$1], JOB=[$2],..., COMM=[$6], DEPTNO=[$7], SLACKER=[$8]) |
| * LogicalFilter(condition=[=($cor0.DEPTNO, $9)]) |
| * LogicalProject(EMPNO=[$0], ENAME=[$1], JOB=[$2],..., SLACKER=[$8], $f9=[+($7, 30)]) |
| * LogicalTableScan(table=[[CATALOG, SALES, EMP]]) |
| * </pre> |
| */ |
| public final class FilterFlattenCorrelatedConditionRule |
| extends RelOptRule { |
| |
| public FilterFlattenCorrelatedConditionRule(Class<? extends Filter> clazz, RelBuilderFactory factory, |
| String description) { |
| super(operand(clazz, any()), factory, description); |
| } |
| |
| @Override public boolean matches(RelOptRuleCall call) { |
| Filter filter = call.rel(0); |
| return RexUtil.containsCorrelation(filter.getCondition()); |
| } |
| |
| @Override public void onMatch(RelOptRuleCall call) { |
| Filter filter = call.rel(0); |
| RelBuilder b = call.builder(); |
| b.push(filter.getInput()); |
| final int proj = b.fields().size(); |
| List<RexNode> projOperands = new ArrayList<>(); |
| RexNode newCondition = filter.getCondition().accept(new RexShuttle() { |
| @Override public RexNode visitCall(RexCall call) { |
| switch (call.getKind()) { |
| case EQUALS: |
| case NOT_EQUALS: |
| case GREATER_THAN: |
| case GREATER_THAN_OR_EQUAL: |
| case LESS_THAN: |
| case LESS_THAN_OR_EQUAL: |
| RexNode op0 = call.operands.get(0); |
| RexNode op1 = call.operands.get(1); |
| final int replaceIndex; |
| if (RexUtil.containsCorrelation(op1) && isUncorrelatedCall(op0)) { |
| replaceIndex = 0; |
| } else if (RexUtil.containsCorrelation(op0) && isUncorrelatedCall(op1)) { |
| replaceIndex = 1; |
| } else { |
| // Structure does not match, do not replace |
| replaceIndex = -1; |
| } |
| if (replaceIndex != -1) { |
| List<RexNode> copyOperands = new ArrayList<>(call.operands); |
| RexNode oldOp = call.operands.get(replaceIndex); |
| RexNode newOp = b.getRexBuilder() |
| .makeInputRef(oldOp.getType(), proj + projOperands.size()); |
| projOperands.add(oldOp); |
| copyOperands.set(replaceIndex, newOp); |
| return call.clone(call.type, copyOperands); |
| } |
| break; |
| case AND: |
| case OR: |
| return super.visitCall(call); |
| } |
| return call; |
| } |
| }); |
| if (newCondition.equals(filter.getCondition())) { |
| return; |
| } |
| b.projectPlus(projOperands); |
| b.filter(newCondition); |
| b.project(b.fields(ImmutableBitSet.range(proj).asList())); |
| call.transformTo(b.build()); |
| } |
| |
| private static boolean isUncorrelatedCall(RexNode node) { |
| return node instanceof RexCall && !RexUtil.containsCorrelation(node); |
| } |
| } |