[
https://issues.apache.org/jira/browse/HIVE-23434?focusedWorklogId=434390&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-434390
]
ASF GitHub Bot logged work on HIVE-23434:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 18/May/20 13:20
Start Date: 18/May/20 13:20
Worklog Time Spent: 10m
Work Description: kgyrtkirk commented on a change in pull request #1017:
URL: https://github.com/apache/hive/pull/1017#discussion_r426620005
##########
File path:
ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/rules/HiveRewriteToDataSketchesRule.java
##########
@@ -0,0 +1,327 @@
+/*
+ * 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 java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Optional;
+
+import org.apache.calcite.plan.RelOptRule;
+import org.apache.calcite.plan.RelOptRuleCall;
+import org.apache.calcite.plan.hep.HepRelVertex;
+import org.apache.calcite.rel.RelCollation;
+import org.apache.calcite.rel.RelNode;
+import org.apache.calcite.rel.core.Aggregate;
+import org.apache.calcite.rel.core.AggregateCall;
+import org.apache.calcite.rel.core.Project;
+import org.apache.calcite.rel.core.RelFactories.ProjectFactory;
+import org.apache.calcite.rel.type.RelDataType;
+import org.apache.calcite.rex.RexBuilder;
+import org.apache.calcite.rex.RexNode;
+import org.apache.calcite.sql.SqlAggFunction;
+import org.apache.calcite.sql.SqlOperator;
+import org.apache.calcite.sql.fun.SqlStdOperatorTable;
+import org.apache.calcite.sql.type.SqlTypeName;
+import org.apache.calcite.util.ImmutableBitSet;
+import org.apache.calcite.util.ImmutableBitSet.Builder;
+import org.apache.hadoop.hive.ql.exec.DataSketchesFunctions;
+import org.apache.hadoop.hive.ql.optimizer.calcite.HiveRelFactories;
+import org.apache.hadoop.hive.ql.optimizer.calcite.reloperators.HiveAggregate;
+import org.apache.hive.plugin.api.HiveUDFPlugin.UDFDescriptor;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Lists;
+
+/**
+ * This rule could rewrite aggregate calls to be calculated using sketch based
functions.
+ *
+ * <br/>
+ * Currently it can rewrite:
+ * <ul>
+ * <li>{@code count(distinct(x))} to distinct counting sketches</li>
+ * <li>{@code percentile_cont(0.2) within group (order by id)}</li>
+ * </ul>
+ *
+ * <p>
+ * The transformation here works on Aggregate nodes; the operations done are
the following:
+ * </p>
+ * <ol>
+ * <li>Identify candidate aggregate calls</li>
+ * <li>A new Project is inserted below the Aggregate; to help with data
pre-processing</li>
+ * <li>A new Aggregate is created in which the aggregation is done by the
sketch function</li>
+ * <li>A new Project is inserted on top of the Aggregate; which unwraps the
resulting
+ * count-distinct estimation from the sketch representation</li>
+ * </ol>
+ */
+public final class HiveRewriteToDataSketchesRule extends RelOptRule {
+
+ protected static final Logger LOG =
LoggerFactory.getLogger(HiveRewriteToDataSketchesRule.class);
+ private final Optional<String> countDistinctSketchType;
+ private final Optional<String> percentileContSketchType;
+ private final ProjectFactory projectFactory;
+
+ public HiveRewriteToDataSketchesRule(Optional<String>
countDistinctSketchType,
+ Optional<String> percentileContSketchType) {
+ super(operand(HiveAggregate.class, any()));
+ this.countDistinctSketchType = countDistinctSketchType;
+ this.percentileContSketchType = percentileContSketchType;
+ projectFactory = HiveRelFactories.HIVE_PROJECT_FACTORY;
+ }
+
+ @Override
+ public void onMatch(RelOptRuleCall call) {
+ final Aggregate aggregate = call.rel(0);
+
+ if (aggregate.getGroupSets().size() != 1) {
+ // not yet supported
+ return;
+ }
+
+ List<AggregateCall> newAggCalls = new ArrayList<AggregateCall>();
+
+ VBuilder vb = new VBuilder(aggregate);
+
+ if (aggregate.getAggCallList().equals(vb.newAggCalls)) {
+ // rule didn't made any changes
+ return;
+ }
+
+ newAggCalls = vb.newAggCalls;
+ List<String> filedNames=new ArrayList<String>();
+ for (int i=0;i<vb.newProjectsBelow.size();i++ ) {
+ filedNames.add("ff_"+i);
+ }
+ RelNode newProjectBelow=
+ projectFactory.createProject(aggregate.getInput(),
vb.newProjectsBelow, filedNames);
+
+ RelNode newAgg = aggregate.copy(aggregate.getTraitSet(), newProjectBelow,
aggregate.getGroupSet(),
+ aggregate.getGroupSets(), newAggCalls);
+
+ RelNode newProject = projectFactory.createProject(newAgg, vb.newProjects,
aggregate.getRowType().getFieldNames());
+
+ call.transformTo(newProject);
+ return;
+ }
+
+ /**
+ * Helper class to help in building a new Aggregate and Project.
+ */
+ // NOTE: methods in this class are not re-entrant; drop-to-frame to
constructor during debugging
+ private class VBuilder {
+
+ private final RexBuilder rexBuilder;
+
+ private Aggregate aggregate;
+ private List<AggregateCall> newAggCalls;
+ private List<RexNode> newProjects;
+ private List<RexNode> newProjectsBelow;
+ private List<RewriteProcedure> rewrites;
+
+ public VBuilder(Aggregate aggregate) {
+ this.aggregate = aggregate;
+ newAggCalls = new ArrayList<AggregateCall>();
+ newProjects = new ArrayList<RexNode>();
+ newProjectsBelow = new ArrayList<RexNode>();
+ rexBuilder = aggregate.getCluster().getRexBuilder();
+ rewrites = new ArrayList<RewriteProcedure>();
+
+ // add identity projections
+ addProjectedFields();
+
+ if (countDistinctSketchType.isPresent()) {
+ rewrites.add(new CountDistinctRewrite(countDistinctSketchType.get()));
+ }
+ if (percentileContSketchType.isPresent()) {
+ rewrites.add(new
PercentileContRewrite(percentileContSketchType.get()));
+ }
+
+ for (AggregateCall aggCall : aggregate.getAggCallList()) {
+ processAggCall(aggCall);
+ }
+ }
+
+ private void addProjectedFields() {
+ for (int i = 0; i < aggregate.getGroupCount(); i++) {
+ newProjects.add(rexBuilder.makeInputRef(aggregate.getInput(), i));
+ }
+ Builder b = ImmutableBitSet.builder();
+ b.addAll(aggregate.getGroupSet());
+ for (AggregateCall aggCall: aggregate.getAggCallList()) {
+ b.addAll(aggCall.getArgList());
+ }
+ ImmutableBitSet inputs = b.build();
+ Integer maxIdx = Collections.max(inputs.asSet());
+ for (int i = 0; i < maxIdx; i++) {
+ newProjectsBelow.add(rexBuilder.makeInputRef(aggregate.getInput(), i));
+ }
+ }
+
+ private void processAggCall(AggregateCall aggCall) {
+ for (RewriteProcedure rewrite : rewrites) {
+ if (rewrite.isApplicable(aggCall)) {
+ rewrite.rewrite(aggCall);
+ return;
+ }
+ }
+ appendAggCall(aggCall);
+ }
+
+ private void appendAggCall(AggregateCall aggCall) {
+ RexNode projRex = rexBuilder.makeInputRef(aggCall.getType(),
newProjects.size());
+
+ newAggCalls.add(aggCall);
+ newProjects.add(projRex);
+ }
+
+ abstract class RewriteProcedure {
+
+ private final String sketchClass;
+
+ public RewriteProcedure(String sketchClass) {
+ this.sketchClass = sketchClass;
+ }
+
+ abstract boolean isApplicable(AggregateCall aggCall);
+ abstract void rewrite(AggregateCall aggCall);
+
+ protected SqlOperator getSqlOperator(String fnName) {
+ UDFDescriptor fn =
DataSketchesFunctions.INSTANCE.getSketchFunction(sketchClass, fnName);
+ if (!fn.getCalciteFunction().isPresent()) {
+ throw new RuntimeException(fn.toString() + " doesn't have a Calcite
function associated with it");
+ }
+ return fn.getCalciteFunction().get();
+ }
+
+ }
+
+ class CountDistinctRewrite extends RewriteProcedure {
+
+ public CountDistinctRewrite(String sketchClass) {
+ super(sketchClass);
+ }
+
+ @Override
+ boolean isApplicable(AggregateCall aggCall) {
+ return aggCall.isDistinct() && aggCall.getArgList().size() == 1
+ && aggCall.getAggregation().getName().equalsIgnoreCase("count") &&
!aggCall.hasFilter();
+ }
+
+ @Override
+ void rewrite(AggregateCall aggCall) {
+ RelDataType origType =
aggregate.getRowType().getFieldList().get(newProjects.size()).getType();
+
+ Integer argIndex = aggCall.getArgList().get(0);
+ RexNode call = rexBuilder.makeInputRef(aggregate.getInput(), argIndex);
+ newProjectsBelow.add(call);
+
+ ArrayList<Integer> newArgList =
Lists.newArrayList(newProjectsBelow.size() - 1);
+
+ SqlAggFunction aggFunction = (SqlAggFunction)
getSqlOperator(DataSketchesFunctions.DATA_TO_SKETCH);
+ boolean distinct = false;
+ boolean approximate = true;
+ boolean ignoreNulls = true;
+ List<Integer> argList = newArgList;
+ int filterArg = aggCall.filterArg;
+ RelCollation collation = aggCall.getCollation();
+ RelDataType type = rexBuilder.deriveReturnType(aggFunction,
Collections.emptyList());
+ String name = aggFunction.getName();
+
+ AggregateCall newAgg = AggregateCall.create(aggFunction, distinct,
approximate, ignoreNulls, argList, filterArg,
+ collation, type, name);
+
+ SqlOperator projectOperator =
getSqlOperator(DataSketchesFunctions.SKETCH_TO_ESTIMATE);
+ RexNode projRex = rexBuilder.makeInputRef(newAgg.getType(),
newProjects.size());
+ projRex = rexBuilder.makeCall(projectOperator,
ImmutableList.of(projRex));
+ projRex = rexBuilder.makeCall(SqlStdOperatorTable.ROUND,
ImmutableList.of(projRex));
+ projRex = rexBuilder.makeCast(origType, projRex);
+
+ newAggCalls.add(newAgg);
+ newProjects.add(projRex);
+ }
+
+ }
+
+ class PercentileContRewrite extends RewriteProcedure {
+
+ public PercentileContRewrite(String sketchClass) {
+ super(sketchClass);
+ }
+
+ @Override
+ boolean isApplicable(AggregateCall aggCall) {
+ // FIXME: also check that args are: ?,?,1,0 - other cases are not
supported
Review comment:
yes it could be fixed later; most importantly it means to support `order
by desc` as well
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Issue Time Tracking
-------------------
Worklog Id: (was: 434390)
Time Spent: 1h 10m (was: 1h)
> Add option to rewrite PERCENTILE_CONT to sketch functions
> ---------------------------------------------------------
>
> Key: HIVE-23434
> URL: https://issues.apache.org/jira/browse/HIVE-23434
> Project: Hive
> Issue Type: Sub-task
> Reporter: Zoltan Haindrich
> Assignee: Zoltan Haindrich
> Priority: Major
> Labels: pull-request-available
> Attachments: HIVE-23434.01.patch, HIVE-23434.02.patch,
> HIVE-23434.03.patch
>
> Time Spent: 1h 10m
> Remaining Estimate: 0h
>
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