How to query table by partition filed?

[jiyis]

Query engine

Iceberg API 1.6.1

Question

How should I query data by partition（bucket） field?

Schema

use s3 store

TableIdentifier tableIdentifier = TableIdentifier.of("default", "example_table");
Schema schema = new Schema(
        Types.NestedField.optional(1, "event_id", Types.StringType.get()),
        Types.NestedField.optional(2, "username", Types.StringType.get()),
        Types.NestedField.optional(3, "userid", Types.IntegerType.get()),
        Types.NestedField.optional(4, "api_version", Types.StringType.get()),
        Types.NestedField.optional(5, "command", Types.StringType.get())
);

PartitionSpec spec = PartitionSpec.builderFor(schema)
        .bucket("event_id", 10)
        .build();

Insert data

TableIdentifier name = TableIdentifier.of("default", "example_table");
Table table = catalog.loadTable(name);
Schema schema = table.schema();
GenericAppenderFactory appenderFactory = new GenericAppenderFactory(schema);

int partitionId = 1, taskId = 1;
OutputFileFactory outputFileFactory = OutputFileFactory.builderFor(table, partitionId, taskId)
        .format(FileFormat.AVRO).build();
final PartitionKey partitionKey = new PartitionKey(table.spec(), table.spec().schema());
PartitionedFanoutWriter<Record> partitionedFanoutWriter = new PartitionedFanoutWriter<>(
        table.spec(),
        FileFormat.AVRO, appenderFactory, outputFileFactory,
        table.io(), 10 * 1024 * 1024) {
    @Override
    protected PartitionKey partition(Record record) {
        partitionKey.partition(record);
        return partitionKey;
    }
};

GenericRecord genericRecord = GenericRecord.create(table.schema());
List<String> levels = Arrays.asList("info", "debug", "error", "warn");
Random random = new Random();
for (int i = 0; i < 10000; i++) {
    GenericRecord record = genericRecord.copy();
    String eventId = UUID.randomUUID().toString();
    record.setField("event_id", eventId);
    record.setField("username", levels.get(random.nextInt(levels.size())));
    record.setField("userid", random.nextInt(10000000));
    record.setField("api_version", "1.0");
    record.setField("command", eventId);
    partitionedFanoutWriter.write(record);
}

AppendFiles appendFiles = table.newAppend();
Arrays.stream(partitionedFanoutWriter.dataFiles()).forEach(appendFiles::appendFile);
Snapshot newSnapshot = appendFiles.apply();
appendFiles.commit();

Query

I'd like to filter data by bucket partition,but it seems that no data is being retrieved. I have confirmed that the data exists, and I can retrieve it using other fields.

 // empty result
  CloseableIterable<Record> result = IcebergGenerics.read(tbl)
         .where(Expressions.equal(
                  "event_id"
                  , "9c83f47c-9a07-4a6b-949c-3bedc31852fe"))
          .build();

 // empty result
  CloseableIterable<Record> result = IcebergGenerics.read(tbl)
         .where(Expressions.equal(Expressions.bucket("event_id", 10), 1))
          .build();

 // has result  Record(9c83f47c-9a07-4a6b-949c-3bedc31852fe, info, 2377306, 1.0, 9c83f47c-9a07-4a6b-949c-3bedc31852fe)
  CloseableIterable<Record> result = IcebergGenerics.read(tbl)
         .where(Expressions.equal(
                  "command"
                  , "9c83f47c-9a07-4a6b-949c-3bedc31852fe"))
          .build();