oleg-zinovev commented on code in PR #12096: URL: https://github.com/apache/ignite/pull/12096#discussion_r3248038264
########## modules/calcite/src/main/java/org/apache/ignite/internal/processors/query/calcite/rel/IgniteWindow.java: ########## @@ -0,0 +1,251 @@ +/* + * 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.ignite.internal.processors.query.calcite.rel; + +import java.util.List; +import com.google.common.collect.ImmutableList; +import org.apache.calcite.plan.RelOptCluster; +import org.apache.calcite.plan.RelOptCost; +import org.apache.calcite.plan.RelOptPlanner; +import org.apache.calcite.plan.RelTraitSet; +import org.apache.calcite.rel.RelCollation; +import org.apache.calcite.rel.RelDistribution; +import org.apache.calcite.rel.RelFieldCollation; +import org.apache.calcite.rel.RelInput; +import org.apache.calcite.rel.RelNode; +import org.apache.calcite.rel.RelWriter; +import org.apache.calcite.rel.core.Window; +import org.apache.calcite.rel.metadata.RelMetadataQuery; +import org.apache.calcite.rel.type.RelDataType; +import org.apache.calcite.rex.RexLiteral; +import org.apache.calcite.util.Pair; +import org.apache.calcite.util.Util; +import org.apache.ignite.internal.processors.query.calcite.externalize.RelInputEx; +import org.apache.ignite.internal.processors.query.calcite.metadata.cost.IgniteCostFactory; +import org.apache.ignite.internal.processors.query.calcite.trait.IgniteDistribution; +import org.apache.ignite.internal.processors.query.calcite.trait.IgniteDistributions; +import org.apache.ignite.internal.processors.query.calcite.trait.TraitUtils; +import org.apache.ignite.internal.processors.query.calcite.util.Commons; +import org.jetbrains.annotations.Nullable; + +import static org.apache.ignite.internal.processors.query.calcite.metadata.cost.IgniteCost.AGG_CALL_MEM_COST; +import static org.apache.ignite.internal.processors.query.calcite.metadata.cost.IgniteCost.AVERAGE_FIELD_SIZE; +import static org.apache.ignite.internal.processors.query.calcite.metadata.cost.IgniteCost.ROW_COMPARISON_COST; +import static org.apache.ignite.internal.processors.query.calcite.trait.TraitUtils.changeTraits; + +/** + * A relational expression representing a set of window aggregates. + * + * <p>A Window can handle several window aggregate functions, over several + * partitions, with pre- and post-expressions, and an optional post-filter. + * Each of the partitions is defined by a partition key (zero or more columns) + * and a range (logical or physical). The partitions expect the data to be + * sorted correctly on input to the relational expression. + * + * <p>Each {@link Window.Group} has a set of + * {@link org.apache.calcite.rex.RexOver} objects. + */ +public class IgniteWindow extends Window implements IgniteRel { + + /** */ + private final Group grp; + + /** */ + private final boolean streaming; + + /** */ + public IgniteWindow( + RelOptCluster cluster, + RelTraitSet traitSet, + RelNode input, + RelDataType rowType, + Group grp, + boolean streaming + ) { + super(cluster, traitSet, input, ImmutableList.of(), rowType, ImmutableList.of(grp)); + this.grp = grp; + this.streaming = streaming; + assert !grp.aggCalls.isEmpty(); + } + + /** */ + public IgniteWindow(RelInput input) { + this(input.getCluster(), + changeTraits(input, IgniteConvention.INSTANCE).getTraitSet(), + input.getInput(), + input.getRowType("rowType"), + ((RelInputEx)input).getWindowGroup("group"), + input.getBoolean("streaming", false)); + } + + /** */ + public Group getGroup() { + return grp; + } + + /** */ + public boolean isStreaming() { + return streaming; + } + + /** {@inheritDoc} */ + @Override public RelNode copy(RelTraitSet traitSet, List<RelNode> inputs) { + return new IgniteWindow(getCluster(), traitSet, sole(inputs), getRowType(), grp, streaming); + } + + /** {@inheritDoc} */ + @Override public Window copy(List<RexLiteral> constants) { + assert constants.isEmpty(); + return this; + } + + /** {@inheritDoc} */ + @Override public <T> T accept(IgniteRelVisitor<T> visitor) { + return visitor.visit(this); + } + + /** {@inheritDoc} */ + @Override public IgniteRel clone(RelOptCluster cluster, List<IgniteRel> inputs) { + return new IgniteWindow(cluster, getTraitSet(), sole(inputs), getRowType(), grp, streaming); + } + + /** {@inheritDoc} */ + @Override public RelWriter explainTerms(RelWriter pw) { + return pw + .input("input", getInput()) + .item("rowType", getRowType()) + .item("group", grp) + .item("streaming", streaming); + } + + /** {@inheritDoc} */ + @Override public RelOptCost computeSelfCost(RelOptPlanner planner, RelMetadataQuery mq) { + IgniteCostFactory costFactory = (IgniteCostFactory)planner.getCostFactory(); + + int aggCnt = grp.aggCalls.size(); + + double rowCnt = mq.getRowCount(getInput()); + double cpuCost = rowCnt * ROW_COMPARISON_COST; + double memCost = (getRowType().getFieldCount() * AVERAGE_FIELD_SIZE + aggCnt * AGG_CALL_MEM_COST) * (streaming ? 1.0 : rowCnt); + + RelOptCost cost = costFactory.makeCost(rowCnt, cpuCost, 0, memCost, 0); + + // Distributed processing is more preferable than processing on the single node. + if (TraitUtils.distribution(traitSet).satisfies(IgniteDistributions.single())) + cost = cost.plus(costFactory.makeTinyCost()); + + return cost; + } + + /** {@inheritDoc} */ + @Override public Pair<RelTraitSet, List<RelTraitSet>> passThroughTraits(RelTraitSet required) { + RelTraitSet traits = passThroughOrDerivedTraits(required); + if (traits == null) + return null; + + return Pair.of(traits, ImmutableList.of(traits)); + } + + /** {@inheritDoc} */ + @Override public Pair<RelTraitSet, List<RelTraitSet>> deriveTraits(RelTraitSet childTraits, int childId) { + assert childId == 0; + + RelTraitSet traits = passThroughOrDerivedTraits(childTraits); + if (traits == null) + return null; + + return Pair.of(traits, ImmutableList.of(traits)); + } + + /** + * Propagates the trait set from the parent to the child, or derives it from the child node. + * + * <p>The Window node cannot independently satisfy any traits. Therefore: + * - Validate that collation and distribution traits are compatible with the Window node. + * - If they are not, replace them with suitable traits. + * - Request a new trait set from the input accordingly. + */ + private @Nullable RelTraitSet passThroughOrDerivedTraits(RelTraitSet target) { + if (target.getConvention() != IgniteConvention.INSTANCE) + return null; + + RelTraitSet traits = target; + RelCollation requiredCollation = TraitUtils.collation(target); + if (!satisfiesCollationSansGroupFields(requiredCollation)) { + traits = traits.replace(collation()); + } + + IgniteDistribution distribution = TraitUtils.distribution(target); + if (!satisfiesDistribution(distribution)) + traits = traits.replace(distribution()); + else if (distribution.getType() == RelDistribution.Type.HASH_DISTRIBUTED) { + // Group set contains all distribution keys, shift distribution keys according to used columns. + IgniteDistribution outDistribution = distribution.apply(Commons.mapping(grp.keys, rowType.getFieldCount())); + traits = traits.replace(outDistribution); + } + + if (traits == traitSet) { + // new traits equal to current traits of window. + // no need to pass throught or derive any. + return null; + } + + return traits; + } + + /** Check input distribution satisfies collation of this window. */ + private boolean satisfiesDistribution(IgniteDistribution distribution) { + if (distribution.satisfies(IgniteDistributions.single()) || distribution.function().correlated()) { Review Comment: @alex-plekhanov Hi, That’s a very good observation, and it helped me improve my understanding of the derive/passThrough mechanism. I’m currently revisiting the IgniteWindow implementation related to this. -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
