org.apache.drill.exec.planner.physical

Interface PartitionFunction

All Known Implementing Classes:

AbstractRangePartitionFunction, JsonTableRangePartitionFunction

public interface PartitionFunction

Method Summary

Modifier and Type	Method and Description
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
List<FieldReference>	getPartitionRefList() Return the list of FieldReferences that participate in the partitioning function
void	setup(List<VectorWrapper<?>> partitionKeys) Setup method for the partitioning function

Method Detail

getPartitionRefList

List<FieldReference> getPartitionRefList()

Return the list of FieldReferences that participate in the partitioning function

Returns:

list of FieldReferences

setup

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

Setup method for the partitioning function

Parameters:

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

eval

int eval(int index,
         int numPartitions)

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

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

FieldReference getPartitionFieldRef()

Returns a FieldReference (LogicalExpression) for the partition function

Returns:

FieldReference for the partition function