somandal commented on code in PR #10286: URL: https://github.com/apache/pinot/pull/10286#discussion_r1123269986
########## pinot-query-runtime/src/main/java/org/apache/pinot/query/runtime/operator/WindowAggregateOperator.java: ########## @@ -0,0 +1,332 @@ +/** + * 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.pinot.query.runtime.operator; + +import com.google.common.annotations.VisibleForTesting; +import com.google.common.base.Preconditions; +import com.google.common.collect.ImmutableList; +import java.util.ArrayList; +import java.util.HashMap; +import java.util.HashSet; +import java.util.List; +import java.util.Map; +import java.util.Set; +import java.util.function.Function; +import java.util.stream.Collectors; +import javax.annotation.Nullable; +import org.apache.calcite.rel.RelFieldCollation; +import org.apache.commons.collections.CollectionUtils; +import org.apache.pinot.common.datablock.DataBlock; +import org.apache.pinot.common.utils.DataSchema; +import org.apache.pinot.core.data.table.Key; +import org.apache.pinot.query.planner.logical.RexExpression; +import org.apache.pinot.query.routing.VirtualServerAddress; +import org.apache.pinot.query.runtime.blocks.TransferableBlock; +import org.apache.pinot.query.runtime.blocks.TransferableBlockUtils; +import org.apache.pinot.query.runtime.operator.utils.AggregationUtils; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + + +/** + * The WindowAggregateOperator is used to compute window function aggregations over a set of optional + * PARTITION BY keys, ORDER BY keys and a FRAME clause. The output data will include the projected + * columns and in addition will add the aggregation columns to the output data. + * [input columns, aggregate result1, ... aggregate resultN] + * + * The window functions supported today are SUM/COUNT/MIN/MAX/AVG/BOOL_OR/BOOL_AND aggregations. Window functions also + * include other types of functions such as rank and value functions. + * + * Unlike the AggregateOperator which will output one row per group, the WindowAggregateOperator + * will output as many rows as input rows. + * + * Note: This class performs aggregation over the double value of input. + * If the input is single value, the output type will be input type. Otherwise, the output type will be double. Review Comment: This comment is copied over from `AggregateOperator` (since both use the `AggregationUtils`) and basically discusses that if only a single input is part of the aggregation, then the `Merger::initialize()` function today doesn't cast it as a double, so the output won't be a double. For other cases it does use the double value: ``` default Object initialize(Object other, DataSchema.ColumnDataType dataType) { // TODO: Initialize as a double so that if only one row is returned it matches the type when many rows are // returned return other == null ? dataType.getNullPlaceholder() : other; } ``` Example merger function: ``` private static Object mergeMax(Object left, Object right) { return Math.max(((Number) left).doubleValue(), ((Number) right).doubleValue()); } ``` I tried to fix this but ran into a bunch of test issues so decided to try and fix the `initialize` to also use `doubleValue()` in a separate PR if possible. Also wanted context on why the code was written in this way. Hope this clarifies the comment. -- 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: commits-unsubscr...@pinot.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For additional commands, e-mail: commits-h...@pinot.apache.org
