vvysotskyi commented on a change in pull request #1441: DRILL-6703: Query with complex expressions in lateral and unnest fails with CannotPlanException URL: https://github.com/apache/drill/pull/1441#discussion_r212394250
########## File path: exec/java-exec/src/main/java/org/apache/drill/exec/planner/sql/handlers/ComplexUnnestVisitor.java ########## @@ -0,0 +1,195 @@ +/* + * 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.drill.exec.planner.sql.handlers; + +import com.google.common.collect.ImmutableList; +import org.apache.calcite.plan.RelOptUtil; +import org.apache.calcite.rel.RelNode; +import org.apache.calcite.rel.RelShuttleImpl; +import org.apache.calcite.rel.core.Correlate; +import org.apache.calcite.rel.core.CorrelationId; +import org.apache.calcite.rel.core.Project; +import org.apache.calcite.rel.core.Uncollect; +import org.apache.calcite.rel.logical.LogicalCorrelate; +import org.apache.calcite.rel.type.RelDataTypeField; +import org.apache.calcite.rex.RexBuilder; +import org.apache.calcite.rex.RexFieldAccess; +import org.apache.calcite.rex.RexNode; +import org.apache.calcite.rex.RexShuttle; +import org.apache.calcite.sql.SqlKind; +import org.apache.calcite.tools.RelBuilder; +import org.apache.calcite.util.ImmutableBitSet; +import org.apache.drill.exec.planner.logical.DrillRelFactories; + +import java.util.ArrayList; +import java.util.Arrays; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.stream.Collectors; + +/** + * Visitor that moves non-{@link RexFieldAccess} rex node from project below {@link Uncollect} + * to the left side of the {@link Correlate}. + */ +public class ComplexUnnestVisitor extends RelShuttleImpl { + private static final String COMPLEX_FIELD_NAME = "$COMPLEX_FIELD_NAME"; + + private final Map<CorrelationId, RelNode> leftInputs = new HashMap<>(); + private final Map<CorrelationId, CorrelationId> updatedCorrelationIds = new HashMap<>(); + + private ComplexUnnestVisitor() { + } + + @Override + public RelNode visit(LogicalCorrelate correlate) { + RelNode left = correlate.getLeft().accept(this); + leftInputs.put(correlate.getCorrelationId(), left); + + RelNode right = correlate.getRight().accept(this); + // if right input wasn't changed or left input wasn't changed + // after rewriting right input, no need to create Correlate with new CorrelationId + if (correlate.getRight() == right + || left == leftInputs.get(correlate.getCorrelationId())) { + if (correlate.getLeft() == left) { + return correlate; + } + // changed only inputs, but CorrelationId left the same + return correlate.copy(correlate.getTraitSet(), Arrays.asList(left, right)); + } + + Correlate newCorrelate = correlate.copy(correlate.getTraitSet(), + leftInputs.get(correlate.getCorrelationId()), right, + updatedCorrelationIds.get(correlate.getCorrelationId()), + ImmutableBitSet.of(left.getRowType().getFieldCount()), correlate.getJoinType()); + + RelBuilder builder = DrillRelFactories.LOGICAL_BUILDER.create(correlate.getCluster(), null); + builder.push(newCorrelate); + + List<RexNode> topProjectExpressions = left.getRowType().getFieldList().stream() + .map(field -> builder.getRexBuilder().makeInputRef(left, field.getIndex())) + .collect(Collectors.toList()); + + switch (correlate.getJoinType()) { + case LEFT: + case INNER: + // adds field from the right input of correlate to the top project + topProjectExpressions.add( + builder.getRexBuilder().makeInputRef(newCorrelate, topProjectExpressions.size() + 1)); + // fall through + case ANTI: + case SEMI: + builder.project(topProjectExpressions, correlate.getRowType().getFieldNames()); + } + return builder.build(); + } + + @Override + public RelNode visit(RelNode other) { + if (other instanceof Uncollect) { + return visit((Uncollect) other); + } + return super.visit(other); + } + + public RelNode visit(Uncollect uncollect) { + RelBuilder builder = DrillRelFactories.LOGICAL_BUILDER.create(uncollect.getCluster(), null); + RexBuilder rexBuilder = builder.getRexBuilder(); + + assert uncollect.getInput() instanceof Project : "Uncollect should have Project input"; Review comment: In the case, if at this point we have something that differs from Project, then something went wrong. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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