rahulsmahadev commented on code in PR #17622: URL: https://github.com/apache/iceberg/pull/17622#discussion_r4291120774
########## spark/v4.1/spark/src/main/java/org/apache/iceberg/spark/actions/RepairMetrics.java: ########## @@ -0,0 +1,268 @@ +/* + * 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.spark.actions; + +import static org.apache.iceberg.TableProperties.DEFAULT_NAME_MAPPING; + +import java.nio.ByteBuffer; +import java.util.List; +import java.util.Map; +import java.util.Objects; +import java.util.Set; +import org.apache.iceberg.ContentFile; +import org.apache.iceberg.DataFile; +import org.apache.iceberg.DataFiles; +import org.apache.iceberg.DeleteFile; +import org.apache.iceberg.FileContent; +import org.apache.iceberg.FileFormat; +import org.apache.iceberg.FileMetadata; +import org.apache.iceberg.MetadataColumns; +import org.apache.iceberg.Metrics; +import org.apache.iceberg.MetricsConfig; +import org.apache.iceberg.MetricsUtil; +import org.apache.iceberg.PartitionSpec; +import org.apache.iceberg.Schema; +import org.apache.iceberg.Table; +import org.apache.iceberg.avro.Avro; +import org.apache.iceberg.io.InputFile; +import org.apache.iceberg.mapping.NameMapping; +import org.apache.iceberg.mapping.NameMappingParser; +import org.apache.iceberg.orc.OrcMetrics; +import org.apache.iceberg.parquet.ParquetUtil; +import org.apache.iceberg.relocated.com.google.common.collect.ImmutableMap; +import org.apache.iceberg.relocated.com.google.common.collect.ImmutableSet; +import org.apache.iceberg.relocated.com.google.common.collect.Maps; +import org.apache.iceberg.relocated.com.google.common.collect.Sets; +import org.apache.iceberg.types.Type; +import org.apache.iceberg.types.TypeUtil; + +/** + * Reads the statistics of data and delete files and compares them against the statistics recorded + * in manifest entries. + * + * <p>Recomputed statistics always respect the metrics config of the table so that they are + * comparable with the stored statistics. + */ +class RepairMetrics { + + private static final Set<Integer> POSITION_DELETE_FIELD_IDS = + ImmutableSet.of( + MetadataColumns.DELETE_FILE_PATH.fieldId(), MetadataColumns.DELETE_FILE_POS.fieldId()); + + private RepairMetrics() {} + + /** Returns the name mapping of the table, or null if the table does not define one. */ + static NameMapping nameMapping(Table table) { + String mapping = table.properties().get(DEFAULT_NAME_MAPPING); + return mapping != null ? NameMappingParser.fromJson(mapping) : null; + } + + /** + * Returns the metrics config to use when recomputing the statistics of the given file. + * + * <p>Position delete files record statistics for the path and position columns only, which is a + * fixed config rather than the config of the table. + */ + static MetricsConfig metricsConfig(Table table, FileContent content) { + return content == FileContent.POSITION_DELETES + ? MetricsConfig.forPositionDelete() + : MetricsConfig.forTable(table); + } + + /** + * Returns true if the statistics of the file can be recomputed by reading it. + * + * <p>Deletion vectors are stored as blobs inside a Puffin file, so their statistics cannot be + * derived by reading the file they are stored in. + */ + static boolean supportsMetrics(ContentFile<?> file) { + FileFormat format = file.format(); + return format == FileFormat.PARQUET || format == FileFormat.ORC || format == FileFormat.AVRO; + } + + /** Recomputes recoverable statistics, preserving metrics that require writer-side tracking. */ + static Metrics readMetrics( + InputFile input, + ContentFile<?> file, + MetricsConfig config, + NameMapping mapping, + Schema schema) { + Metrics metrics = + switch (file.format()) { + case PARQUET -> ParquetUtil.fileMetrics(input, config, mapping); + case ORC -> OrcMetrics.fromInputFile(input, config, mapping); + case AVRO -> new Metrics(Avro.rowCount(input)); + default -> + throw new UnsupportedOperationException( + "Cannot read metrics of format: " + file.format()); + }; + if (file.format() == FileFormat.AVRO) { + return recordCountOnly(file, metrics); + } + + if (file.content() == FileContent.POSITION_DELETES) { + // Match PositionDeleteWriter: counts are omitted, and bounds are kept only for a single path. + int pathId = MetadataColumns.DELETE_FILE_PATH.fieldId(); + ByteBuffer lowerPath = normalize(metrics.lowerBounds()).get(pathId); + ByteBuffer upperPath = normalize(metrics.upperBounds()).get(pathId); + metrics = + lowerPath != null && lowerPath.equals(upperPath) + ? MetricsUtil.copyWithoutFieldCounts(metrics, POSITION_DELETE_FIELD_IDS) + : MetricsUtil.copyWithoutFieldCountsAndBounds(metrics, POSITION_DELETE_FIELD_IDS); + } + + // Footers cannot recover the writer-tracked statistics of some columns: the NaN counts and + // NaN-safe bounds of floating-point columns, and the bounding boxes of geometry and geography + // columns. Preserve the stored bounds of those columns so a correct file is not flagged as + // corrupt and rewritten with weaker statistics. Include stored NaN-count IDs so that bounds for + // dropped columns are preserved as well. + Set<Integer> preservedBoundIds = Sets.newHashSet(normalize(file.nanValueCounts()).keySet()); + TypeUtil.indexById(schema.asStruct()) + .forEach( + (id, field) -> { + Type.TypeID typeId = field.type().typeId(); + if (typeId == Type.TypeID.FLOAT + || typeId == Type.TypeID.DOUBLE + || typeId == Type.TypeID.GEOMETRY + || typeId == Type.TypeID.GEOGRAPHY) { + preservedBoundIds.add(id); + } + }); + + return new Metrics( + metrics.recordCount(), + metrics.columnSizes(), + metrics.valueCounts(), + metrics.nullValueCounts(), + file.nanValueCounts(), + preserveBounds(file.lowerBounds(), metrics.lowerBounds(), preservedBoundIds), + preserveBounds(file.upperBounds(), metrics.upperBounds(), preservedBoundIds), + file.totalBytes(), + null); + } + + /** + * Returns true if the statistics recorded for the file differ from the statistics of the file + * itself. + * + * <p>The record count and the file size are always compared. Column level statistics are only + * compared when requested, because a table whose metrics config changed after a file was written + * reports statistics that legitimately differ from the recomputed ones. + */ + static boolean statsAreIncorrect( Review Comment: Done -- 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]
