gortiz commented on code in PR #8979: URL: https://github.com/apache/pinot/pull/8979#discussion_r913463570
########## pinot-core/src/main/java/org/apache/pinot/core/operator/query/SelectionPartiallyOrderedByOperator.java: ########## @@ -0,0 +1,303 @@ +/** + * 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.operator.query; + +import com.google.common.base.Preconditions; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Collections; +import java.util.Comparator; +import java.util.Iterator; +import java.util.List; +import javax.annotation.Nullable; +import org.apache.pinot.common.request.context.ExpressionContext; +import org.apache.pinot.common.request.context.OrderByExpressionContext; +import org.apache.pinot.common.utils.DataSchema; +import org.apache.pinot.core.common.BlockValSet; +import org.apache.pinot.core.common.Operator; +import org.apache.pinot.core.common.RowBasedBlockValueFetcher; +import org.apache.pinot.core.operator.BaseOperator; +import org.apache.pinot.core.operator.ExecutionStatistics; +import org.apache.pinot.core.operator.blocks.IntermediateResultsBlock; +import org.apache.pinot.core.operator.blocks.TransformBlock; +import org.apache.pinot.core.operator.transform.TransformOperator; +import org.apache.pinot.core.operator.transform.TransformResultMetadata; +import org.apache.pinot.core.query.request.context.QueryContext; +import org.apache.pinot.core.query.selection.SelectionOperatorUtils; +import org.apache.pinot.segment.spi.IndexSegment; + + +/** + * An operator for order-by queries that are partially sorted over the sorting keys. + */ +public class SelectionPartiallyOrderedByOperator extends BaseOperator<IntermediateResultsBlock> { + + private static final String EXPLAIN_NAME = "SELECT_PARTIAL_ORDERBY"; + + private final IndexSegment _indexSegment; + + // Deduped order-by expressions followed by output expressions from SelectionOperatorUtils.extractExpressions() + private final List<ExpressionContext> _expressions; + private final List<ExpressionContext> _alreadySorted; + private final List<ExpressionContext> _toSort; + + private final TransformOperator _transformOperator; + private final List<OrderByExpressionContext> _orderByExpressions; + private final TransformResultMetadata[] _expressionsMetadata; + private final int _numRowsToKeep; + private final PartiallySortedListBuilder _sorter; + + private int _numDocsScanned = 0; + private long _numEntriesScannedPostFilter = 0; + private boolean _used = false; + private Comparator<Object[]> _comparator; + + public SelectionPartiallyOrderedByOperator(IndexSegment indexSegment, QueryContext queryContext, + List<ExpressionContext> expressions, TransformOperator transformOperator, int sortedExpr) { + Preconditions.checkArgument(sortedExpr > 0, + "This operator should not be used when sorting expressions doesn't start with sorted expressions"); + _indexSegment = indexSegment; + _expressions = expressions; + _transformOperator = transformOperator; + + _orderByExpressions = queryContext.getOrderByExpressions(); + assert _orderByExpressions != null; + int numOrderByExpressions = _orderByExpressions.size(); + + _alreadySorted = expressions.subList(0, sortedExpr); + _toSort = expressions.subList(sortedExpr, numOrderByExpressions); + + Preconditions.checkArgument(!_toSort.isEmpty(), + "This operator should not be used when all sorting expressions are sorted. " + + "Use %s instead", SelectionOrderByOperator.class.getName()); + + _expressionsMetadata = new TransformResultMetadata[_expressions.size()]; + for (int i = 0; i < _expressionsMetadata.length; i++) { + ExpressionContext expression = _expressions.get(i); + _expressionsMetadata[i] = _transformOperator.getResultMetadata(expression); + } + + _numRowsToKeep = queryContext.getOffset() + queryContext.getLimit(); + + int expectedSize = Math.min(_numRowsToKeep * 2, SelectionOperatorUtils.MAX_ROW_HOLDER_INITIAL_CAPACITY); + Comparator<Object[]> sortedComparator = + SelectionOrderByOperator.getComparator(_orderByExpressions, _expressionsMetadata, true, 0, sortedExpr); + Comparator<Object[]> unsortedComparator = + SelectionOrderByOperator.getComparator(_orderByExpressions, _expressionsMetadata, true, sortedExpr, + numOrderByExpressions); + _sorter = new PartiallySortedListBuilder(expectedSize, sortedComparator, unsortedComparator); + _comparator = SelectionOrderByOperator.getComparator(_orderByExpressions, _expressionsMetadata, false); + } + + @Override + public List<Operator> getChildOperators() { + return Collections.singletonList(_transformOperator); + } + + @Override + protected IntermediateResultsBlock getNextBlock() { + if (!_used) { + _used = true; + fetch(); + + DataSchema dataSchema = createDataSchema(); + + return new IntermediateResultsBlock.ListSelection(dataSchema, _sorter.build(), _comparator); Review Comment: We create one `SelectionPartiallyOrderedByOperator` per query per segment, right? So yeah, we build one `sorter` for each query per segment. Remember that `_sorter.build()` does not generate memory, it just returns the list it used internally and it shouldn't be used again. -- 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
