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GH-3828: Preserve column path identity in dictionary lookup #3830

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GH-3828: Preserve column path identity in dictionary lookup #3830

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15 changes: 8 additions & 7 deletions parquet-hadoop/src/main/java/org/apache/parquet/hadoop/DictionaryPageReader.java
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Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,7 @@
import org.apache.parquet.column.page.DictionaryPageReadStore;
import org.apache.parquet.hadoop.metadata.BlockMetaData;
import org.apache.parquet.hadoop.metadata.ColumnChunkMetaData;
import org.apache.parquet.hadoop.metadata.ColumnPath;
import org.apache.parquet.io.ParquetDecodingException;

/**
Expand All @@ -44,8 +45,8 @@
class DictionaryPageReader implements DictionaryPageReadStore {

private final ParquetFileReader reader;
private final Map<String, ColumnChunkMetaData> columns;
private final Map<String, Optional<DictionaryPage>> dictionaryPageCache;
private final Map<ColumnPath, ColumnChunkMetaData> columns;
private final Map<ColumnPath, Optional<DictionaryPage>> dictionaryPageCache;
private ColumnChunkPageReadStore rowGroup = null;
private ByteBufferReleaser releaser;

Expand All @@ -64,7 +65,7 @@ class DictionaryPageReader implements DictionaryPageReadStore {
releaser = new ByteBufferReleaser(allocator);

for (ColumnChunkMetaData column : block.getColumns()) {
columns.put(column.getPath().toDotString(), column);
columns.put(column.getPath(), column);
}
}

Expand All @@ -87,14 +88,14 @@ public DictionaryPage readDictionaryPage(ColumnDescriptor descriptor) {
return rowGroup.readDictionaryPage(descriptor);
}

String dotPath = String.join(".", descriptor.getPath());
ColumnChunkMetaData column = columns.get(dotPath);
ColumnPath path = ColumnPath.get(descriptor.getPath());
ColumnChunkMetaData column = columns.get(path);
if (column == null) {
throw new ParquetDecodingException("Failed to load dictionary, unknown column: " + dotPath);
throw new ParquetDecodingException("Failed to load dictionary, unknown column: " + path);
}

return dictionaryPageCache
.computeIfAbsent(dotPath, key -> {
.computeIfAbsent(path, key -> {
try {
final DictionaryPage dict = column.hasDictionaryPage() ? reader.readDictionary(column) : null;

Expand Down
58 changes: 58 additions & 0 deletions parquet-hadoop/src/test/java/org/apache/parquet/hadoop/TestParquetWriter.java
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Expand Up @@ -61,11 +61,14 @@
import org.apache.parquet.bytes.HeapByteBufferAllocator;
import org.apache.parquet.bytes.TrackingByteBufferAllocator;
import org.apache.parquet.column.ColumnDescriptor;
import org.apache.parquet.column.Dictionary;
import org.apache.parquet.column.Encoding;
import org.apache.parquet.column.ParquetProperties;
import org.apache.parquet.column.ParquetProperties.WriterVersion;
import org.apache.parquet.column.page.DataPage;
import org.apache.parquet.column.page.DataPageV2;
import org.apache.parquet.column.page.DictionaryPage;
import org.apache.parquet.column.page.DictionaryPageReadStore;
import org.apache.parquet.column.page.PageReadStore;
import org.apache.parquet.column.page.PageReader;
import org.apache.parquet.column.values.bloomfilter.BloomFilter;
Expand Down Expand Up @@ -335,6 +338,61 @@ public void testParquetFileWithBloomFilter() throws IOException {
}
}

@Test
public void testDictionaryReaderKeepsCollidingDotStringPathsDistinct() throws Exception {
MessageType schema = Types.buildMessage()
.required(BINARY)
.as(stringType())
.named("a.b")
.requiredGroup()
.required(BINARY)
.as(stringType())
.named("b")
.named("a")
.named("msg");
Configuration conf = new Configuration();
GroupWriteSupport.setSchema(schema, conf);
GroupFactory factory = new SimpleGroupFactory(schema);

Path path = newTempPath();
try (ParquetWriter<Group> writer = ExampleParquetWriter.builder(path)
.withAllocator(allocator)
.withConf(conf)
.withDictionaryEncoding(true)
.build()) {
for (int i = 0; i < 100; i++) {
String suffix = (i % 2 == 0) ? "one" : "two";
Group group = factory.newGroup().append("a.b", suffix);
group.addGroup("a").append("b", "nested-" + suffix);
writer.write(group);
}
}

try (ParquetFileReader reader = ParquetFileReader.open(HadoopInputFile.fromPath(path, conf))) {
ColumnDescriptor topLevelDescriptor = schema.getColumnDescription(new String[] {"a.b"});
ColumnDescriptor nestedDescriptor = schema.getColumnDescription(new String[] {"a", "b"});
DictionaryPageReadStore dictionaryReader = reader.getNextDictionaryReader();
DictionaryPage topLevelPage = dictionaryReader.readDictionaryPage(topLevelDescriptor);
DictionaryPage nestedPage = dictionaryReader.readDictionaryPage(nestedDescriptor);
assertThat(topLevelPage).isNotNull();
assertThat(nestedPage).isNotNull();

Dictionary topLevelDictionary = topLevelPage.getEncoding().initDictionary(topLevelDescriptor, topLevelPage);
Set<String> topLevelValues = new HashSet<>();
for (int id = 0; id <= topLevelDictionary.getMaxId(); id++) {
topLevelValues.add(topLevelDictionary.decodeToBinary(id).toStringUsingUTF8());
}
assertThat(topLevelValues).containsExactlyInAnyOrder("one", "two");

Dictionary nestedDictionary = nestedPage.getEncoding().initDictionary(nestedDescriptor, nestedPage);
Set<String> nestedValues = new HashSet<>();
for (int id = 0; id <= nestedDictionary.getMaxId(); id++) {
nestedValues.add(nestedDictionary.decodeToBinary(id).toStringUsingUTF8());
}
assertThat(nestedValues).containsExactlyInAnyOrder("nested-one", "nested-two");
}
}

@Test
public void testParquetFileWithBloomFilterWithFpp() throws IOException {
int buildBloomFilterCount = 100000;
Expand Down