org.apache.hadoop.hive.ql.exec.vector

Class VectorizedRowBatch

java.lang.Object

org.apache.hadoop.hive.ql.exec.vector.VectorizedRowBatch

All Implemented Interfaces:

org.apache.hadoop.io.Writable

public class VectorizedRowBatch
extends Object
implements org.apache.hadoop.io.Writable

A VectorizedRowBatch is a set of rows, organized with each column as a vector. It is the unit of query execution, organized to minimize the cost per row and achieve high cycles-per-instruction. The major fields are public by design to allow fast and convenient access by the vectorized query execution code.

Field Summary

Fields

Modifier and Type	Field and Description
ColumnVector[]	cols
static int	DEFAULT_SIZE
boolean	endOfFile
int	numCols
int[]	projectedColumns
int	projectionSize
int[]	selected
boolean	selectedInUse
int	size
VectorExpressionWriter[]	valueWriters

Constructor Summary

Constructors

Constructor and Description
VectorizedRowBatch(int numCols) Return a batch with the specified number of columns.
VectorizedRowBatch(int numCols, int size) Return a batch with the specified number of columns and rows.

Method Summary

Methods

Modifier and Type	Method and Description
long	count() Return count of qualifying rows.
int	getMaxSize() Returns the maximum size of the batch (number of rows it can hold)
void	readFields(DataInput arg0)
void	reset() Resets the row batch to default state - sets selectedInUse to false - sets size to 0 - sets endOfFile to false - resets each column - inits each column
void	setValueWriters(VectorExpressionWriter[] valueWriters)
String	toString()
void	write(DataOutput arg0)

Methods inherited from class java.lang.Object

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

Field Detail

numCols

public int numCols

cols

public ColumnVector[] cols

size

public int size

selected

public int[] selected

projectedColumns

public int[] projectedColumns

projectionSize

public int projectionSize

selectedInUse

public boolean selectedInUse

endOfFile

public boolean endOfFile

DEFAULT_SIZE

public static final int DEFAULT_SIZE

See Also:

Constant Field Values

valueWriters

public VectorExpressionWriter[] valueWriters

Constructor Detail

VectorizedRowBatch

public VectorizedRowBatch(int numCols)

Return a batch with the specified number of columns. This is the standard constructor -- all batches should be the same size

Parameters:

numCols - the number of columns to include in the batch

VectorizedRowBatch

public VectorizedRowBatch(int numCols,
                  int size)

Return a batch with the specified number of columns and rows. Only call this constructor directly for testing purposes. Batch size should normally always be defaultSize.

Parameters:

numCols - the number of columns to include in the batch

size - the number of rows to include in the batch

Method Detail

getMaxSize

public int getMaxSize()

Returns the maximum size of the batch (number of rows it can hold)

count

public long count()

Return count of qualifying rows.

Returns:

number of rows that have not been filtered out

toString

public String toString()

Overrides:

toString in class Object

readFields

public void readFields(DataInput arg0)
                throws IOException

Specified by:

readFields in interface org.apache.hadoop.io.Writable

Throws:

IOException

write

public void write(DataOutput arg0)
           throws IOException

Specified by:

write in interface org.apache.hadoop.io.Writable

Throws:

IOException

setValueWriters

public void setValueWriters(VectorExpressionWriter[] valueWriters)

reset

public void reset()

Resets the row batch to default state - sets selectedInUse to false - sets size to 0 - sets endOfFile to false - resets each column - inits each column