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Merged
ebyhr merged 1 commit into from
Jun 14, 2022
Merged

Attach weights to DeltaLakeSplits #12755

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4 changes: 4 additions & 0 deletions docs/src/main/sphinx/connector/delta-lake.rst
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Original file line number Diff line number Diff line change
Expand Up @@ -180,6 +180,10 @@ connector.
can also use the corresponding catalog session property
``<catalog-name>.max_split_size``.
- ``64MB``
* - ``delta.minimum-assigned-split-weight``
- A decimal value in the range (0, 1] used as a minimum for weights assigned to each split. A low value may improve performance
on tables with small files. A higher value may improve performance for queries with highly skewed aggregations or joins.
- 0.05

The following table describes :ref:`catalog session properties
<session-properties-definition>` supported by the Delta Lake connector to
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18 changes: 18 additions & 0 deletions plugin/trino-delta-lake/src/main/java/io/trino/plugin/deltalake/DeltaLakeConfig.java
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Expand Up @@ -22,6 +22,8 @@
import io.trino.plugin.hive.HiveCompressionCodec;
import org.joda.time.DateTimeZone;

import javax.validation.constraints.DecimalMax;
import javax.validation.constraints.DecimalMin;
import javax.validation.constraints.Min;
import javax.validation.constraints.NotNull;

Expand Down Expand Up @@ -50,6 +52,7 @@ public class DeltaLakeConfig
private int maxInitialSplits = 200;
private DataSize maxInitialSplitSize;
private DataSize maxSplitSize = DataSize.of(64, MEGABYTE);
private double minimumAssignedSplitWeight = 0.05;
private int maxPartitionsPerWriter = 100;
private boolean unsafeWritesEnabled;
private boolean checkpointRowStatisticsWritingEnabled = true;
Expand Down Expand Up @@ -173,6 +176,21 @@ public DeltaLakeConfig setMaxSplitSize(DataSize maxSplitSize)
return this;
}

@Config("delta.minimum-assigned-split-weight")
@ConfigDescription("Minimum weight that a split can be assigned")
public DeltaLakeConfig setMinimumAssignedSplitWeight(double minimumAssignedSplitWeight)
{
this.minimumAssignedSplitWeight = minimumAssignedSplitWeight;
return this;
}

@DecimalMax("1")
@DecimalMin(value = "0", inclusive = false)
public double getMinimumAssignedSplitWeight()
{
return minimumAssignedSplitWeight;
}

@Min(1)
public int getMaxPartitionsPerWriter()
{
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12 changes: 12 additions & 0 deletions plugin/trino-delta-lake/src/main/java/io/trino/plugin/deltalake/DeltaLakeSplit.java
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Expand Up @@ -19,6 +19,7 @@
import com.google.common.collect.ImmutableMap;
import io.airlift.slice.SizeOf;
import io.trino.spi.HostAddress;
import io.trino.spi.SplitWeight;
import io.trino.spi.connector.ConnectorSplit;
import io.trino.spi.predicate.TupleDomain;
import org.openjdk.jol.info.ClassLayout;
Expand All @@ -44,6 +45,7 @@ public class DeltaLakeSplit
private final long fileSize;
private final long fileModifiedTime;
private final List<HostAddress> addresses;
private final SplitWeight splitWeight;
private final TupleDomain<DeltaLakeColumnHandle> statisticsPredicate;
private final Map<String, Optional<String>> partitionKeys;

Expand All @@ -55,6 +57,7 @@ public DeltaLakeSplit(
@JsonProperty("fileSize") long fileSize,
@JsonProperty("fileModifiedTime") long fileModifiedTime,
@JsonProperty("addresses") List<HostAddress> addresses,
@JsonProperty("splitWeight") SplitWeight splitWeight,
@JsonProperty("statisticsPredicate") TupleDomain<DeltaLakeColumnHandle> statisticsPredicate,
@JsonProperty("partitionKeys") Map<String, Optional<String>> partitionKeys)
{
Expand All @@ -64,6 +67,7 @@ public DeltaLakeSplit(
this.fileSize = fileSize;
this.fileModifiedTime = fileModifiedTime;
this.addresses = ImmutableList.copyOf(requireNonNull(addresses, "addresses is null"));
this.splitWeight = requireNonNull(splitWeight, "splitWeight is null");
this.statisticsPredicate = requireNonNull(statisticsPredicate, "statisticsPredicate is null");
this.partitionKeys = requireNonNull(partitionKeys, "partitionKeys is null");
}
Expand All @@ -81,6 +85,13 @@ public List<HostAddress> getAddresses()
return addresses;
}

@JsonProperty
@Override
public SplitWeight getSplitWeight()
{
return splitWeight;
}

@JsonProperty
public String getPath()
{
Expand Down Expand Up @@ -132,6 +143,7 @@ public long getRetainedSizeInBytes()
return INSTANCE_SIZE
+ estimatedSizeOf(path)
+ estimatedSizeOf(addresses, HostAddress::getRetainedSizeInBytes)
+ splitWeight.getRetainedSizeInBytes()
+ statisticsPredicate.getRetainedSizeInBytes(DeltaLakeColumnHandle::getRetainedSizeInBytes)
+ estimatedSizeOf(partitionKeys, SizeOf::estimatedSizeOf, value -> sizeOf(value, SizeOf::estimatedSizeOf));
}
Expand Down
14 changes: 9 additions & 5 deletions plugin/trino-delta-lake/src/main/java/io/trino/plugin/deltalake/DeltaLakeSplitManager.java
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Expand Up @@ -19,6 +19,7 @@
import io.trino.plugin.deltalake.metastore.DeltaLakeMetastore;
import io.trino.plugin.deltalake.transactionlog.AddFileEntry;
import io.trino.plugin.hive.HiveTransactionHandle;
import io.trino.spi.SplitWeight;
import io.trino.spi.connector.ColumnHandle;
import io.trino.spi.connector.ColumnMetadata;
import io.trino.spi.connector.ConnectorSession;
Expand Down Expand Up @@ -70,6 +71,7 @@ public class DeltaLakeSplitManager
private final int maxInitialSplits;
private final int maxSplitsPerSecond;
private final int maxOutstandingSplits;
private final double minimumAssignedSplitWeight;

@Inject
public DeltaLakeSplitManager(
Expand All @@ -85,6 +87,7 @@ public DeltaLakeSplitManager(
this.maxInitialSplits = config.getMaxInitialSplits();
this.maxSplitsPerSecond = config.getMaxSplitsPerSecond();
this.maxOutstandingSplits = config.getMaxOutstandingSplits();
this.minimumAssignedSplitWeight = config.getMinimumAssignedSplitWeight();
}

@Override
Expand Down Expand Up @@ -235,22 +238,22 @@ private List<DeltaLakeSplit> splitsForFile(
fileSize,
addFileEntry.getModificationTime(),
ImmutableList.of(),
SplitWeight.standard(),
statisticsPredicate,
partitionKeys));
}

ImmutableList.Builder<DeltaLakeSplit> splits = ImmutableList.builder();
long currentOffset = 0;
while (currentOffset < fileSize) {
long splitSize;
long maxSplitSize;
if (remainingInitialSplits.get() > 0 && remainingInitialSplits.getAndDecrement() > 0) {
splitSize = getMaxInitialSplitSize(session).toBytes();
maxSplitSize = getMaxInitialSplitSize(session).toBytes();
}
else {
splitSize = getMaxSplitSize(session).toBytes();
maxSplitSize = getMaxSplitSize(session).toBytes();
}

splitSize = Math.min(splitSize, fileSize - currentOffset);
long splitSize = Math.min(maxSplitSize, fileSize - currentOffset);

splits.add(new DeltaLakeSplit(
splitPath,
Expand All @@ -259,6 +262,7 @@ private List<DeltaLakeSplit> splitsForFile(
fileSize,
addFileEntry.getModificationTime(),
ImmutableList.of(),
SplitWeight.fromProportion(Math.min(Math.max((double) splitSize / maxSplitSize, minimumAssignedSplitWeight), 1.0)),
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@findepi findepi Jun 14, 2022

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Math.min( ..., 1) is redundant per my understanding.

nit: static import min & max

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@findepi findepi Jun 14, 2022

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Math.min( ..., 1) is redundant per my understanding.

ie if we somehow end up creating an oversized split, it's fine to let the engine know about that.

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@findepi findepi Jun 14, 2022

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#12832

statisticsPredicate,
partitionKeys));

Expand Down
3 changes: 3 additions & 0 deletions plugin/trino-delta-lake/src/test/java/io/trino/plugin/deltalake/TestDeltaLakeConfig.java
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Expand Up @@ -46,6 +46,7 @@ public void testDefaults()
.setMaxInitialSplits(200)
.setMaxInitialSplitSize(DataSize.of(32, DataSize.Unit.MEGABYTE))
.setMaxSplitSize(DataSize.of(64, DataSize.Unit.MEGABYTE))
.setMinimumAssignedSplitWeight(0.05)
.setMaxPartitionsPerWriter(100)
.setUnsafeWritesEnabled(false)
.setDefaultCheckpointWritingInterval(10)
Expand Down Expand Up @@ -74,6 +75,7 @@ public void testExplicitPropertyMappings()
.put("delta.max-initial-splits", "5")
.put("delta.max-initial-split-size", "1 GB")
.put("delta.max-split-size", "10 MB")
.put("delta.minimum-assigned-split-weight", "0.01")
.put("delta.max-partitions-per-writer", "200")
.put("delta.enable-non-concurrent-writes", "true")
.put("delta.default-checkpoint-writing-interval", "15")
Expand All @@ -99,6 +101,7 @@ public void testExplicitPropertyMappings()
.setMaxInitialSplits(5)
.setMaxInitialSplitSize(DataSize.of(1, DataSize.Unit.GIGABYTE))
.setMaxSplitSize(DataSize.of(10, DataSize.Unit.MEGABYTE))
.setMinimumAssignedSplitWeight(0.01)
.setMaxPartitionsPerWriter(200)
.setUnsafeWritesEnabled(true)
.setDefaultCheckpointWritingInterval(15)
Expand Down
41 changes: 23 additions & 18 deletions ...n/trino-delta-lake/src/test/java/io/trino/plugin/deltalake/TestDeltaLakeSplitManager.java
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Expand Up @@ -29,6 +29,7 @@
import io.trino.plugin.hive.metastore.Table;
import io.trino.plugin.hive.parquet.ParquetReaderConfig;
import io.trino.plugin.hive.parquet.ParquetWriterConfig;
import io.trino.spi.SplitWeight;
import io.trino.spi.connector.ConnectorSession;
import io.trino.spi.connector.ConnectorSplit;
import io.trino.spi.connector.ConnectorSplitManager;
Expand Down Expand Up @@ -89,15 +90,16 @@ public void testInitialSplits()
DeltaLakeConfig deltaLakeConfig = new DeltaLakeConfig()
.setMaxInitialSplits(1000)
.setMaxInitialSplitSize(DataSize.ofBytes(5_000));
double minimumAssignedSplitWeight = deltaLakeConfig.getMinimumAssignedSplitWeight();

DeltaLakeSplitManager splitManager = setupSplitManager(addFileEntries, deltaLakeConfig);
List<DeltaLakeSplit> splits = getSplits(splitManager, deltaLakeConfig);

List<DeltaLakeSplit> expected = ImmutableList.of(
makeSplit(0, 5_000, fileSize),
makeSplit(5_000, 5_000, fileSize),
makeSplit(10_000, 5_000, fileSize),
makeSplit(15_000, 5_000, fileSize));
makeSplit(0, 5_000, fileSize, minimumAssignedSplitWeight),
makeSplit(5_000, 5_000, fileSize, minimumAssignedSplitWeight),
makeSplit(10_000, 5_000, fileSize, minimumAssignedSplitWeight),
makeSplit(15_000, 5_000, fileSize, minimumAssignedSplitWeight));

assertEquals(splits, expected);
}
Expand All @@ -112,18 +114,19 @@ public void testNonInitialSplits()
.setMaxInitialSplits(5)
.setMaxInitialSplitSize(DataSize.ofBytes(5_000))
.setMaxSplitSize(DataSize.ofBytes(20_000));
double minimumAssignedSplitWeight = deltaLakeConfig.getMinimumAssignedSplitWeight();

DeltaLakeSplitManager splitManager = setupSplitManager(addFileEntries, deltaLakeConfig);
List<DeltaLakeSplit> splits = getSplits(splitManager, deltaLakeConfig);

List<DeltaLakeSplit> expected = ImmutableList.of(
makeSplit(0, 5_000, fileSize),
makeSplit(5_000, 5_000, fileSize),
makeSplit(10_000, 5_000, fileSize),
makeSplit(15_000, 5_000, fileSize),
makeSplit(20_000, 5_000, fileSize),
makeSplit(25_000, 20_000, fileSize),
makeSplit(45_000, 5_000, fileSize));
makeSplit(0, 5_000, fileSize, minimumAssignedSplitWeight),
makeSplit(5_000, 5_000, fileSize, minimumAssignedSplitWeight),
makeSplit(10_000, 5_000, fileSize, minimumAssignedSplitWeight),
makeSplit(15_000, 5_000, fileSize, minimumAssignedSplitWeight),
makeSplit(20_000, 5_000, fileSize, minimumAssignedSplitWeight),
makeSplit(25_000, 20_000, fileSize, minimumAssignedSplitWeight),
makeSplit(45_000, 5_000, fileSize, minimumAssignedSplitWeight));

assertEquals(splits, expected);
}
Expand All @@ -139,16 +142,17 @@ public void testSplitsFromMultipleFiles()
.setMaxInitialSplits(3)
.setMaxInitialSplitSize(DataSize.ofBytes(2_000))
.setMaxSplitSize(DataSize.ofBytes(10_000));
double minimumAssignedSplitWeight = deltaLakeConfig.getMinimumAssignedSplitWeight();

DeltaLakeSplitManager splitManager = setupSplitManager(addFileEntries, deltaLakeConfig);

List<DeltaLakeSplit> splits = getSplits(splitManager, deltaLakeConfig);
List<DeltaLakeSplit> expected = ImmutableList.of(
makeSplit(0, 1_000, firstFileSize),
makeSplit(0, 2_000, secondFileSize),
makeSplit(2_000, 2_000, secondFileSize),
makeSplit(4_000, 10_000, secondFileSize),
makeSplit(14_000, 6_000, secondFileSize));
makeSplit(0, 1_000, firstFileSize, minimumAssignedSplitWeight),
makeSplit(0, 2_000, secondFileSize, minimumAssignedSplitWeight),
makeSplit(2_000, 2_000, secondFileSize, minimumAssignedSplitWeight),
makeSplit(4_000, 10_000, secondFileSize, minimumAssignedSplitWeight),
makeSplit(14_000, 6_000, secondFileSize, minimumAssignedSplitWeight));
assertEquals(splits, expected);
}

Expand All @@ -171,9 +175,10 @@ private AddFileEntry addFileEntryOfSize(long fileSize)
return new AddFileEntry(FILE_PATH, ImmutableMap.of(), fileSize, 0, false, Optional.empty(), Optional.empty(), ImmutableMap.of());
}

private DeltaLakeSplit makeSplit(long start, long splitSize, long fileSize)
private DeltaLakeSplit makeSplit(long start, long splitSize, long fileSize, double minimumAssignedSplitWeight)
{
return new DeltaLakeSplit(FULL_PATH, start, splitSize, fileSize, 0, ImmutableList.of(), TupleDomain.all(), ImmutableMap.of());
SplitWeight splitWeight = SplitWeight.fromProportion(Math.min(Math.max((double) fileSize / splitSize, minimumAssignedSplitWeight), 1.0));
return new DeltaLakeSplit(FULL_PATH, start, splitSize, fileSize, 0, ImmutableList.of(), splitWeight, TupleDomain.all(), ImmutableMap.of());
}

private List<DeltaLakeSplit> getSplits(DeltaLakeSplitManager splitManager, DeltaLakeConfig deltaLakeConfig)
Expand Down