Package org.apache.drill.exec.store.parquet.columnreaders

Class BatchReader.MockBatchReader

java.lang.Object

org.apache.drill.exec.store.parquet.columnreaders.BatchReader

org.apache.drill.exec.store.parquet.columnreaders.BatchReader.MockBatchReader

Enclosing class:

BatchReader

public static class BatchReader.MockBatchReader
extends BatchReader

Strategy for reading mock records. Mock records appear to occur in the case in which the query has SELECT a, b, but the Parquet file has only c, d. A mock scan reads dummy columns for all records to ensure that the batch contains a record for each Parquet record, but with no data per record. (This explanation is reverse-engineered from the code and may be wrong. Caveat emptor!)

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.drill.exec.store.parquet.columnreaders.BatchReader

BatchReader.FixedWidthReader, BatchReader.MockBatchReader, BatchReader.VariableWidthReader

Field Summary

Fields inherited from class org.apache.drill.exec.store.parquet.columnreaders.BatchReader

readState

Constructor Summary

Constructors

Constructor	Description
MockBatchReader(ReadState readState)

Method Summary

Modifier and Type	Method	Description
protected int	readRecords(ColumnReader<?> firstColumnStatus, long recordsToRead)

Methods inherited from class org.apache.drill.exec.store.parquet.columnreaders.BatchReader

readAllFixedFields, readAllFixedFieldsParallel, readAllFixedFieldsSerial, readBatch

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

MockBatchReader

public MockBatchReader(ReadState readState)

Method Details

readRecords

protected int readRecords(ColumnReader<?> firstColumnStatus,
 long recordsToRead)

Specified by:

readRecords in class BatchReader