org.apache.drill.exec.planner.physical

Class AbstractRangePartitionFunction

java.lang.Object

org.apache.drill.exec.planner.physical.AbstractRangePartitionFunction

All Implemented Interfaces:

PartitionFunction

public abstract class AbstractRangePartitionFunction
extends Object
implements PartitionFunction

Field Summary

Fields

Modifier and Type	Field and Description
static String	RANGE_PARTITION_EXPR_NAME

Constructor Summary

Constructors

Constructor and Description
AbstractRangePartitionFunction()

Method Summary

Modifier and Type	Method and Description
abstract int	eval(int index, int numPartitions) Evaluate a partitioning function for a particular row index and return the partition id
FieldReference	getPartitionFieldRef() Returns a FieldReference (LogicalExpression) for the partition function
abstract List<FieldReference>	getPartitionRefList() Return the list of FieldReferences that participate in the partitioning function
abstract void	setup(List<VectorWrapper<?>> partitionKeys) Setup method for the partitioning function

Methods inherited from class java.lang.Object

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

Field Detail

RANGE_PARTITION_EXPR_NAME

public static final String RANGE_PARTITION_EXPR_NAME

See Also:

Constant Field Values

Constructor Detail

AbstractRangePartitionFunction

public AbstractRangePartitionFunction()

Method Detail

getPartitionRefList

public abstract List<FieldReference> getPartitionRefList()

Description copied from interface: PartitionFunction

Return the list of FieldReferences that participate in the partitioning function

Specified by:

getPartitionRefList in interface PartitionFunction

Returns:

list of FieldReferences

setup

public abstract void setup(List<VectorWrapper<?>> partitionKeys)

Description copied from interface: PartitionFunction

Setup method for the partitioning function

Specified by:

setup in interface PartitionFunction

Parameters:

partitionKeys - a list of partition columns on which range partitioning is needed

eval

public abstract int eval(int index,
                         int numPartitions)

Description copied from interface: PartitionFunction

Evaluate a partitioning function for a particular row index and return the partition id

Specified by:

eval in interface PartitionFunction

Parameters:

index - the integer index into the partition keys vector for a specific 'row' of values

numPartitions - the max number of partitions that are allowed

Returns:

partition id, an integer value

getPartitionFieldRef

public FieldReference getPartitionFieldRef()

Description copied from interface: PartitionFunction

Returns a FieldReference (LogicalExpression) for the partition function

Specified by:

getPartitionFieldRef in interface PartitionFunction

Returns:

FieldReference for the partition function