org.apache.hadoop.hive.ql.io.orc

Interface Reader

All Superinterfaces:

org.apache.orc.Reader

All Known Subinterfaces:

Reader

public interface Reader
extends org.apache.orc.Reader

The interface for reading ORC files. One Reader can support multiple concurrent RecordReader.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.orc.Reader

org.apache.orc.Reader.Options

Method Summary

Modifier and Type	Method and Description
CompressionKind	getCompression() Get the Compression kind in the compatibility mode.
ObjectInspector	getObjectInspector() Get the object inspector for looking at the objects.
RecordReader	rows() Create a RecordReader that reads everything with the default options.
RecordReader	rows(boolean[] include) Create a RecordReader that will scan the entire file.
RecordReader	rows(long offset, long length, boolean[] include) Create a RecordReader that will start reading at the first stripe after offset up to the stripe that starts at offset + length.
RecordReader	rows(long offset, long length, boolean[] include, org.apache.hadoop.hive.ql.io.sarg.SearchArgument sarg, String[] neededColumns) Create a RecordReader that will read a section of a file.
RecordReader	rowsOptions(org.apache.orc.Reader.Options options) Create a RecordReader that reads everything with the given options.
RecordReader	rowsOptions(org.apache.orc.Reader.Options options, org.apache.hadoop.conf.Configuration conf) Create a RecordReader that reads everything with the given options.

Methods inherited from interface org.apache.orc.Reader

getCompressionKind, getCompressionSize, getContentLength, getFileTail, getFileVersion, getMetadataKeys, getMetadataSize, getMetadataValue, getNumberOfRows, getOrcProtoFileStatistics, getOrcProtoStripeStatistics, getRawDataSize, getRawDataSizeFromColIndices, getRawDataSizeOfColumns, getRowIndexStride, getSchema, getSerializedFileFooter, getStatistics, getStripes, getStripeStatistics, getTypes, getVersionList, getWriterVersion, hasMetadataValue, options, rows

Method Detail

getObjectInspector

ObjectInspector getObjectInspector()

Get the object inspector for looking at the objects.

Returns:

an object inspector for each row returned

getCompression

CompressionKind getCompression()

Get the Compression kind in the compatibility mode.

rows

RecordReader rows()
           throws IOException

Create a RecordReader that reads everything with the default options.

Specified by:

rows in interface org.apache.orc.Reader

Returns:

a new RecordReader

Throws:

IOException

rowsOptions

RecordReader rowsOptions(org.apache.orc.Reader.Options options)
                  throws IOException

Create a RecordReader that reads everything with the given options.

Parameters:

options - the options to use

Returns:

a new RecordReader

Throws:

IOException

rowsOptions

RecordReader rowsOptions(org.apache.orc.Reader.Options options,
                         org.apache.hadoop.conf.Configuration conf)
                  throws IOException

Create a RecordReader that reads everything with the given options.

Parameters:

options - the options to use

conf - conf object

Returns:

a new RecordReader

Throws:

IOException

rows

RecordReader rows(boolean[] include)
           throws IOException

Create a RecordReader that will scan the entire file. This is a legacy method and rowsOptions is preferred.

Parameters:

include - true for each column that should be included

Returns:

A new RecordReader

Throws:

IOException

rows

RecordReader rows(long offset,
                  long length,
                  boolean[] include)
           throws IOException

Create a RecordReader that will start reading at the first stripe after offset up to the stripe that starts at offset + length. This is intended to work with MapReduce's FileInputFormat where divisions are picked blindly, but they must cover all of the rows. This is a legacy method and rowsOptions is preferred.

Parameters:

offset - a byte offset in the file

length - a number of bytes in the file

include - true for each column that should be included

Returns:

a new RecordReader that will read the specified rows.

Throws:

IOException

rows

RecordReader rows(long offset,
                  long length,
                  boolean[] include,
                  org.apache.hadoop.hive.ql.io.sarg.SearchArgument sarg,
                  String[] neededColumns)
           throws IOException

Create a RecordReader that will read a section of a file. It starts reading at the first stripe after the offset and continues to the stripe that starts at offset + length. It also accepts a list of columns to read and a search argument. This is a legacy method and rowsOptions is preferred.

Parameters:

offset - the minimum offset of the first stripe to read

length - the distance from offset of the first address to stop reading at

include - true for each column that should be included

sarg - a search argument that limits the rows that should be read.

neededColumns - the names of the included columns

Returns:

the record reader for the rows

Throws:

IOException