org.apache.tajo.storage

Interface Appender

All Superinterfaces:

AutoCloseable, Closeable

public interface Appender
extends Closeable

Interface for appender. Every appender that writes some data to underlying storage needs to implement this interface.

Method Summary

Methods

Modifier and Type	Method and Description
void	addTuple(Tuple t) Write the given tuple.
void	close() Close the appender.
void	enableStats() Enable statistics collection for the output table.
void	enableStats(List<Column> columnList) Enable statistics collection for the output table as well as its columns.
void	flush() Flush buffered tuples if they exist.
long	getEstimatedOutputSize() The total size of written output.
TableStats	getStats() Return collected statistics.
void	init() Initialize the appender.

Method Detail

init

void init()
          throws IOException

Initialize the appender.

Throws:

IOException

addTuple

void addTuple(Tuple t)
              throws IOException

Write the given tuple.

Parameters:

t -

Throws:

IOException

flush

void flush()
           throws IOException

Flush buffered tuples if they exist.

Throws:

IOException

getEstimatedOutputSize

long getEstimatedOutputSize()
                            throws IOException

The total size of written output. The result value can be different from the real size due to the buffered data.

Returns:

Throws:

IOException

close

void close()
           throws IOException

Close the appender.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException

enableStats

void enableStats()

Enable statistics collection for the output table.

enableStats

void enableStats(List<Column> columnList)

Enable statistics collection for the output table as well as its columns. Note that statistics are collected on only the specified columns.

Parameters:

columnList - a list of columns on which statistics is collected

getStats

TableStats getStats()

Return collected statistics.

Returns:

statistics