aokolnychyi commented on code in PR #6304: URL: https://github.com/apache/iceberg/pull/6304#discussion_r1035346108
########## core/src/main/java/org/apache/iceberg/util/TableScanUtil.java: ########## @@ -151,38 +153,68 @@ public static <T extends PartitionScanTask> List<ScanTaskGroup<T>> planTaskGroup Function<T, Long> weightFunc = task -> Math.max(task.sizeBytes(), task.filesCount() * openFileCost); - Map<Integer, StructProjection> projectionsBySpec = Maps.newHashMap(); + Map<Integer, StructProjection> groupingKeyProjectionsBySpec = Maps.newHashMap(); - // Group tasks by their partition values - StructLikeMap<List<T>> tasksByPartition = StructLikeMap.create(projectedPartitionType); + // group tasks by grouping keys derived from their partition tuples + StructLikeMap<List<T>> tasksByGroupingKey = StructLikeMap.create(groupingKeyType); for (T task : tasks) { PartitionSpec spec = task.spec(); - StructProjection projectedStruct = - projectionsBySpec.computeIfAbsent( + StructProjection groupingKeyProjection = + groupingKeyProjectionsBySpec.computeIfAbsent( spec.specId(), - specId -> StructProjection.create(spec.partitionType(), projectedPartitionType)); - List<T> taskList = - tasksByPartition.computeIfAbsent( - projectedStruct.copyFor(task.partition()), k -> Lists.newArrayList()); + specId -> StructProjection.create(spec.partitionType(), groupingKeyType)); + List<T> groupingKeyTasks = + tasksByGroupingKey.computeIfAbsent( + projectGroupingKey(groupingKeyProjection, groupingKeyType, task), + groupingKey -> Lists.newArrayList()); if (task instanceof SplittableScanTask<?>) { - ((SplittableScanTask<? extends T>) task).split(splitSize).forEach(taskList::add); + ((SplittableScanTask<? extends T>) task).split(splitSize).forEach(groupingKeyTasks::add); } else { - taskList.add(task); + groupingKeyTasks.add(task); } } - // Now apply task combining within each partition - return FluentIterable.from(tasksByPartition.values()) - .transformAndConcat(ts -> toTaskGroupIterable(ts, splitSize, lookback, weightFunc)) - .toList(); + List<ScanTaskGroup<T>> taskGroups = Lists.newArrayList(); + + for (Map.Entry<StructLike, List<T>> entry : tasksByGroupingKey.entrySet()) { + StructLike groupingKey = entry.getKey(); + List<T> groupingKeyTasks = entry.getValue(); + Iterables.addAll( + taskGroups, + toTaskGroupIterable(groupingKey, groupingKeyTasks, splitSize, lookback, weightFunc)); + } + + return taskGroups; + } + + private static StructLike projectGroupingKey( + StructProjection groupingKeyProjection, + Types.StructType groupingKeyType, + PartitionScanTask task) { + + PartitionData groupingKey = new PartitionData(groupingKeyType); + + groupingKeyProjection.wrap(task.partition()); Review Comment: Correct, but this would mean I no longer project the key in that method, so I'll have to rename it to something like `copyAsPartitionData`. That would make the method disconnected from the fact that we project this key from the partition, so using `PartitionData` for the key would be weird. On top, Spotless formatted the new code in a less readable way, which I can't change. I see your point but given that I can't change Spotless formatting, do you mind if I keep it this way? -- 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