pvary commented on code in PR #9321: URL: https://github.com/apache/iceberg/pull/9321#discussion_r1433664382
########## flink/v1.17/flink/src/main/java/org/apache/iceberg/flink/sink/shuffle/MapRangePartitioner.java: ########## @@ -0,0 +1,288 @@ +/* + * 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.iceberg.flink.sink.shuffle; + +import java.util.Arrays; +import java.util.Comparator; +import java.util.Iterator; +import java.util.List; +import java.util.Map; +import java.util.NavigableMap; +import java.util.concurrent.ThreadLocalRandom; +import org.apache.flink.api.common.functions.Partitioner; +import org.apache.flink.table.data.RowData; +import org.apache.iceberg.Schema; +import org.apache.iceberg.SortKey; +import org.apache.iceberg.SortOrder; +import org.apache.iceberg.SortOrderComparators; +import org.apache.iceberg.StructLike; +import org.apache.iceberg.flink.FlinkSchemaUtil; +import org.apache.iceberg.flink.RowDataWrapper; +import org.apache.iceberg.relocated.com.google.common.annotations.VisibleForTesting; +import org.apache.iceberg.relocated.com.google.common.base.MoreObjects; +import org.apache.iceberg.relocated.com.google.common.base.Preconditions; +import org.apache.iceberg.relocated.com.google.common.collect.Lists; +import org.apache.iceberg.relocated.com.google.common.collect.Maps; +import org.apache.iceberg.util.ArrayUtil; +import org.apache.iceberg.util.Pair; + +/** + * Internal partitioner implementation that supports MapDataStatistics, which is typically used for + * low-cardinality use cases. While MapDataStatistics can keep accurate counters, it can't be used + * for high-cardinality use cases. Otherwise, the memory footprint is too high. + */ +class MapRangePartitioner implements Partitioner<RowData> { + private final RowDataWrapper rowDataWrapper; + private final SortKey sortKey; + private final Comparator<StructLike> comparator; + private final Map<SortKey, Long> mapStatistics; + private final double closeFileCostInWeightPercentage; + + // lazily computed due to the need of numPartitions + private Map<SortKey, KeyAssignment> assignment; + private NavigableMap<SortKey, Long> sortedStatsWithCloseFileCost; + + MapRangePartitioner( + Schema schema, + SortOrder sortOrder, + MapDataStatistics dataStatistics, + double closeFileCostInWeightPercentage) { + this.rowDataWrapper = new RowDataWrapper(FlinkSchemaUtil.convert(schema), schema.asStruct()); + this.sortKey = new SortKey(schema, sortOrder); + this.comparator = SortOrderComparators.forSchema(schema, sortOrder); + this.mapStatistics = dataStatistics.statistics(); + this.closeFileCostInWeightPercentage = closeFileCostInWeightPercentage; + } + + @Override + public int partition(RowData row, int numPartitions) { + // assignment table can only be built lazily when first referenced here, + // because number of partitions (downstream subtasks) is needed + Map<SortKey, KeyAssignment> assignmentMap = assignment(numPartitions); + // reuse the sortKey and rowDataWrapper + sortKey.wrap(rowDataWrapper.wrap(row)); + KeyAssignment keyAssignment = assignmentMap.get(sortKey); + if (keyAssignment == null) { + // haven't learned about the key before. fall back to random selection. + return ThreadLocalRandom.current().nextInt(numPartitions); Review Comment: I leave this to you. My only concern is that one of the goals was to keep the number of files to small, and this will likely create `numPartitions` number of files. If the new keys cardinality is high, then it is good, but if the new keys cardinality is low, then this is an issue. But if we need this config later, we can add whenever the requirement pops up. -- 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: issues-unsubscr...@iceberg.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@iceberg.apache.org For additional commands, e-mail: issues-h...@iceberg.apache.org
