praveenc7 commented on code in PR #16678: URL: https://github.com/apache/pinot/pull/16678#discussion_r2641492989
########## pinot-core/src/main/java/org/apache/pinot/core/query/aggregation/function/AnyValueAggregationFunction.java: ########## @@ -0,0 +1,377 @@ +/** + * 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.core.query.aggregation.function; + +import java.math.BigDecimal; +import java.nio.ByteBuffer; +import java.nio.charset.StandardCharsets; +import java.util.List; +import java.util.Map; +import org.apache.pinot.common.CustomObject; +import org.apache.pinot.common.request.context.ExpressionContext; +import org.apache.pinot.common.utils.DataSchema.ColumnDataType; +import org.apache.pinot.core.common.BlockValSet; +import org.apache.pinot.core.query.aggregation.AggregationResultHolder; +import org.apache.pinot.core.query.aggregation.ObjectAggregationResultHolder; +import org.apache.pinot.core.query.aggregation.groupby.GroupByResultHolder; +import org.apache.pinot.core.query.aggregation.groupby.ObjectGroupByResultHolder; +import org.apache.pinot.segment.spi.AggregationFunctionType; +import org.apache.pinot.segment.spi.index.reader.Dictionary; +import org.apache.pinot.spi.data.FieldSpec; + + +/** + * AnyValue aggregation function returns any arbitrary NON-NULL value from the column for each group. + * <p> + * This is useful for GROUP BY queries where you want to include a column in SELECT that has a 1:1 mapping with the + * GROUP BY columns, avoiding the need to add it to GROUP BY clause. The implementation is null-aware and will scan + * only until it finds the first non-null value in the current batch for each group/key. This makes it O(n) over the + * input once per group until the first value is set, with early-exit fast paths when there are no nulls. + * </p> + * <p><strong>Example:</strong></p> + * <pre>{@code + * SELECT CustomerID, + * ANY_VALUE(CustomerName), + * SUM(OrderValue) + * FROM Orders + * GROUP BY CustomerID + * }</pre> + */ +public class AnyValueAggregationFunction extends NullableSingleInputAggregationFunction<Object, Comparable<?>> { + // Result type is determined at runtime based on input expression type + private ColumnDataType _resultType; + + public AnyValueAggregationFunction(List<ExpressionContext> arguments, boolean nullHandlingEnabled) { + super(verifySingleArgument(arguments, "ANY_VALUE"), nullHandlingEnabled); + _resultType = null; + } + + @Override + public AggregationFunctionType getType() { + return AggregationFunctionType.ANYVALUE; + } + + @Override + public AggregationResultHolder createAggregationResultHolder() { + return new ObjectAggregationResultHolder(); + } + + @Override + public GroupByResultHolder createGroupByResultHolder(int initialCapacity, int maxCapacity) { + return new ObjectGroupByResultHolder(initialCapacity, maxCapacity); + } + + @Override + public ColumnDataType getIntermediateResultColumnType() { + // Default to STRING if result type is not yet determined + // TODO: See if UNKNOWN can be used instead + return _resultType != null ? _resultType : ColumnDataType.STRING; + } + + @Override + public ColumnDataType getFinalResultColumnType() { + return _resultType != null ? _resultType : ColumnDataType.STRING; + } Review Comment: No, it would break type information in query responses. For specific types (INT, LONG, etc.), it performs proper type conversion. For OBJECT, it just returns (Serializable) value without conversion. @yashmayya Let me take a look at the PR you have, Thanks! -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
