clintropolis commented on a change in pull request #6951: Add more sketch aggregator support in Druid SQL URL: https://github.com/apache/incubator-druid/pull/6951#discussion_r252911893
########## File path: extensions-core/datasketches/src/main/java/org/apache/druid/query/aggregation/datasketches/quantiles/sql/DoublesSketchSqlAggregator.java ########## @@ -0,0 +1,245 @@ +/* + * 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.druid.query.aggregation.datasketches.quantiles.sql; + +import com.google.common.collect.ImmutableList; +import org.apache.calcite.rel.core.AggregateCall; +import org.apache.calcite.rel.core.Project; +import org.apache.calcite.rex.RexBuilder; +import org.apache.calcite.rex.RexLiteral; +import org.apache.calcite.rex.RexNode; +import org.apache.calcite.sql.SqlAggFunction; +import org.apache.calcite.sql.SqlFunctionCategory; +import org.apache.calcite.sql.SqlKind; +import org.apache.calcite.sql.type.OperandTypes; +import org.apache.calcite.sql.type.ReturnTypes; +import org.apache.calcite.sql.type.SqlTypeFamily; +import org.apache.calcite.sql.type.SqlTypeName; +import org.apache.druid.java.util.common.StringUtils; +import org.apache.druid.query.aggregation.AggregatorFactory; +import org.apache.druid.query.aggregation.datasketches.quantiles.DoublesSketchAggregatorFactory; +import org.apache.druid.query.aggregation.datasketches.quantiles.DoublesSketchToQuantilePostAggregator; +import org.apache.druid.query.aggregation.post.FieldAccessPostAggregator; +import org.apache.druid.segment.VirtualColumn; +import org.apache.druid.segment.column.ValueType; +import org.apache.druid.segment.virtual.ExpressionVirtualColumn; +import org.apache.druid.sql.calcite.aggregation.Aggregation; +import org.apache.druid.sql.calcite.aggregation.SqlAggregator; +import org.apache.druid.sql.calcite.expression.DruidExpression; +import org.apache.druid.sql.calcite.expression.Expressions; +import org.apache.druid.sql.calcite.planner.PlannerContext; +import org.apache.druid.sql.calcite.table.RowSignature; + +import javax.annotation.Nullable; +import java.util.ArrayList; +import java.util.List; + +public class DoublesSketchSqlAggregator implements SqlAggregator +{ + private static final SqlAggFunction FUNCTION_INSTANCE = new DoublesSketchSqlAggFunction(); + private static final String NAME = "APPROX_QUANTILE_DS"; + + @Override + public SqlAggFunction calciteFunction() + { + return FUNCTION_INSTANCE; + } + + @Nullable + @Override + public Aggregation toDruidAggregation( + final PlannerContext plannerContext, + final RowSignature rowSignature, + final RexBuilder rexBuilder, + final String name, + final AggregateCall aggregateCall, + final Project project, + final List<Aggregation> existingAggregations, + final boolean finalizeAggregations + ) + { + final DruidExpression input = Expressions.toDruidExpression( + plannerContext, + rowSignature, + Expressions.fromFieldAccess( + rowSignature, + project, + aggregateCall.getArgList().get(0) + ) + ); + if (input == null) { + return null; + } + + final AggregatorFactory aggregatorFactory; + final String histogramName = StringUtils.format("%s:agg", name); + final RexNode probabilityArg = Expressions.fromFieldAccess( + rowSignature, + project, + aggregateCall.getArgList().get(1) + ); + + if (!probabilityArg.isA(SqlKind.LITERAL)) { + // Probability must be a literal in order to plan. + return null; + } + + final float probability = ((Number) RexLiteral.value(probabilityArg)).floatValue(); + final int k; + + if (aggregateCall.getArgList().size() >= 3) { + final RexNode resolutionArg = Expressions.fromFieldAccess( + rowSignature, + project, + aggregateCall.getArgList().get(2) + ); + + if (!resolutionArg.isA(SqlKind.LITERAL)) { + // Resolution must be a literal in order to plan. + return null; + } + + k = ((Number) RexLiteral.value(resolutionArg)).intValue(); + } else { + k = DoublesSketchAggregatorFactory.DEFAULT_K; + } + + // Look for existing matching aggregatorFactory. + for (final Aggregation existing : existingAggregations) { + for (AggregatorFactory factory : existing.getAggregatorFactories()) { + if (factory instanceof DoublesSketchAggregatorFactory) { + final DoublesSketchAggregatorFactory theFactory = (DoublesSketchAggregatorFactory) factory; + + // Check input for equivalence. + final boolean inputMatches; + final VirtualColumn virtualInput = existing.getVirtualColumns() + .stream() + .filter( + virtualColumn -> + virtualColumn.getOutputName() + .equals(theFactory.getFieldName()) + ) + .findFirst() + .orElse(null); + + if (virtualInput == null) { + inputMatches = input.isDirectColumnAccess() + && input.getDirectColumn().equals(theFactory.getFieldName()); + } else { + inputMatches = ((ExpressionVirtualColumn) virtualInput).getExpression() + .equals(input.getExpression()); + } + + final boolean matches = inputMatches + && theFactory.getK() == k; + + if (matches) { + // Found existing one. Use this. + return Aggregation.create( + ImmutableList.of(), + new DoublesSketchToQuantilePostAggregator( + name, + new FieldAccessPostAggregator( + factory.getName(), + factory.getName() + ), + probability + ) + ); + } + } + } + } + + // No existing match found. Create a new one. + final List<VirtualColumn> virtualColumns = new ArrayList<>(); + + if (input.isDirectColumnAccess()) { + if (rowSignature.getColumnType(input.getDirectColumn()) == ValueType.COMPLEX) { + aggregatorFactory = new DoublesSketchAggregatorFactory( + histogramName, + input.getDirectColumn(), + k + ); + } else { + aggregatorFactory = new DoublesSketchAggregatorFactory( Review comment: Is this block the same as the `if` condition? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@druid.apache.org For additional commands, e-mail: commits-h...@druid.apache.org
