wypoon commented on code in PR #10935:
URL: https://github.com/apache/iceberg/pull/10935#discussion_r1717121087
##########
core/src/main/java/org/apache/iceberg/BaseIncrementalChangelogScan.java:
##########
@@ -133,51 +131,155 @@ private static Map<Long, Integer>
computeSnapshotOrdinals(Deque<Snapshot> snapsh
return snapshotOrdinals;
}
- private static class CreateDataFileChangeTasks implements
CreateTasksFunction<ChangelogScanTask> {
- private static final DeleteFile[] NO_DELETES = new DeleteFile[0];
+ private Map<String, Integer> computeDeleteFileToSnapshotOrdinal(
+ Deque<Snapshot> snapshots, Map<Long, Integer> snapshotOrdinals) {
+ Map<String, Integer> deleteFileToSnapshotOrdinal = Maps.newHashMap();
+
+ for (Snapshot snapshot : snapshots) {
+ Iterable<DeleteFile> deleteFiles =
snapshot.addedDeleteFiles(table().io());
+ for (DeleteFile deleteFile : deleteFiles) {
+ deleteFileToSnapshotOrdinal.put(
+ deleteFile.path().toString(),
snapshotOrdinals.get(snapshot.snapshotId()));
+ }
+ }
+
+ return deleteFileToSnapshotOrdinal;
+ }
+
+ private static class DummyChangelogScanTask implements ChangelogScanTask {
+ private int changeOrdinal;
+ private long commitSnapshotId;
+ DummyChangelogScanTask(int changeOrdinal, long commitSnapshotId) {
+ this.changeOrdinal = changeOrdinal;
+ this.commitSnapshotId = commitSnapshotId;
+ }
+
+ @Override
+ public ChangelogOperation operation() {
+ return ChangelogOperation.DELETE;
+ }
+
+ @Override
+ public int changeOrdinal() {
+ return changeOrdinal;
+ }
+
+ @Override
+ public long commitSnapshotId() {
+ return commitSnapshotId;
+ }
+ }
+
+ private static class CreateDataFileChangeTasks implements
CreateTasksFunction<ChangelogScanTask> {
+ private final long snapshotId;
+ private final int changeOrdinal;
private final Map<Long, Integer> snapshotOrdinals;
+ private final Map<String, Integer> deleteFileToSnapshotOrdinal;
+
+ CreateDataFileChangeTasks(
+ long snapshotId,
+ Map<Long, Integer> snapshotOrdinals,
+ Map<String, Integer> deleteFileToSnapshotOrdinal) {
+ this.snapshotId = snapshotId;
+ this.snapshotOrdinals = snapshotOrdinals;
+ this.deleteFileToSnapshotOrdinal = deleteFileToSnapshotOrdinal;
+ this.changeOrdinal = this.snapshotOrdinals.get(snapshotId);
+ }
+
+ private DeleteFile[] filterAdded(DeleteFile[] deleteFiles) {
+ return FluentIterable.from(deleteFiles)
+ .filter(
+ deleteFile ->
+
deleteFileToSnapshotOrdinal.get(deleteFile.path().toString()) == changeOrdinal)
+ .toArray(DeleteFile.class);
+ }
- CreateDataFileChangeTasks(Deque<Snapshot> snapshots) {
- this.snapshotOrdinals = computeSnapshotOrdinals(snapshots);
+ private DeleteFile[] filterExisting(DeleteFile[] deleteFiles) {
+ return FluentIterable.from(deleteFiles)
+ .filter(
+ deleteFile ->
+
deleteFileToSnapshotOrdinal.get(deleteFile.path().toString()) < changeOrdinal)
+ .toArray(DeleteFile.class);
}
@Override
public CloseableIterable<ChangelogScanTask> apply(
CloseableIterable<ManifestEntry<DataFile>> entries, TaskContext
context) {
- return CloseableIterable.transform(
- entries,
- entry -> {
- long commitSnapshotId = entry.snapshotId();
- int changeOrdinal = snapshotOrdinals.get(commitSnapshotId);
- DataFile dataFile = entry.file().copy(context.shouldKeepStats());
-
- switch (entry.status()) {
- case ADDED:
- return new BaseAddedRowsScanTask(
- changeOrdinal,
- commitSnapshotId,
- dataFile,
- NO_DELETES,
- context.schemaAsString(),
- context.specAsString(),
- context.residuals());
-
- case DELETED:
- return new BaseDeletedDataFileScanTask(
- changeOrdinal,
- commitSnapshotId,
- dataFile,
- NO_DELETES,
- context.schemaAsString(),
- context.specAsString(),
- context.residuals());
-
- default:
- throw new IllegalArgumentException("Unexpected entry status: "
+ entry.status());
- }
- });
+ CloseableIterable<ChangelogScanTask> tasks =
+ CloseableIterable.transform(
+ entries,
+ entry -> {
+ long entrySnapshotId = entry.snapshotId();
+ DataFile dataFile =
entry.file().copy(context.shouldKeepStats());
+ DeleteFile[] addedDeleteFiles =
filterAdded(context.deletes().forEntry(entry));
+
+ switch (entry.status()) {
+ case ADDED:
+ if (entrySnapshotId == snapshotId) {
+ return new BaseAddedRowsScanTask(
+ changeOrdinal,
+ snapshotId,
+ dataFile,
+ addedDeleteFiles,
+ context.schemaAsString(),
+ context.specAsString(),
+ context.residuals());
+ } else {
+ // the data file is added before the snapshot we're
processing
+ if (addedDeleteFiles.length == 0) {
+ return new DummyChangelogScanTask(changeOrdinal,
snapshotId);
+ } else {
+ return new BaseDeletedRowsScanTask(
+ changeOrdinal,
+ snapshotId,
+ dataFile,
+ addedDeleteFiles,
+ // not used
+ filterExisting(context.deletes().forEntry(entry)),
+ context.schemaAsString(),
+ context.specAsString(),
+ context.residuals());
+ }
+ }
+
+ case DELETED:
+ if (entrySnapshotId == snapshotId) {
+ return new BaseDeletedDataFileScanTask(
+ changeOrdinal,
+ snapshotId,
+ dataFile,
+ filterExisting(context.deletes().forEntry(entry)),
+ context.schemaAsString(),
+ context.specAsString(),
+ context.residuals());
+ } else {
+ return new DummyChangelogScanTask(changeOrdinal,
snapshotId);
+ }
+
+ case EXISTING:
+ if (addedDeleteFiles.length == 0) {
+ return new DummyChangelogScanTask(changeOrdinal,
snapshotId);
+ } else {
+ return new BaseDeletedRowsScanTask(
Review Comment:
Note that a BaseDeletedRowsScanTask is only created if there are delete
files *added in that snapshot* that may apply to the data file.
Supposing that there is an equality delete file added in that snapshot,
whether a full table scan happens for that snapshot depends on the equality
deletes and how well `DeleteFileIndex.canContainEqDeletesForFile(DataFile,
EqualityDeleteFile)` is able to filter them. If the equality deletes are for a
partition, or even if global but can be excluded using ranges, then a full
table scan may not happen. But yes, depending on the equality deletes it could
happen.
Unfortunately, I don't see an alternative.
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