com.pervasive.datarush.ports.record

Interface PartitioningFunction

All Known Implementing Classes:

HashPartitioningFunction, HBasePartitioningFunction, RangePartitioningFunction

public interface PartitioningFunction

Represents a pluggable partitioning function; for use by operators that require custom partitioning

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	PartitioningFunction.Evaluator Computes partition assignments for each row if input

Method Summary

Modifier and Type	Method and Description
PartitioningFunction.Evaluator	getEvaluator(PartitioningFunctionContext ctx) Create an Evaluator bound to the specified context.
boolean	isEquivalentPartitioning(PartitioningFunction other) Returns true iff, given a single row of input, this function is guaranteed to produce the same partitioning as the other function.
boolean	isFunctionOfInput() Returns true iff, given two identical rows of input, this function will return the same value.
PartitioningFunction	remapFieldReferences(Map<String,String> oldToNewMapping) Creates a new function, equivalent to the given function, but with all field references renamed according to the given mapping.
void	validateForType(RecordTokenType type) Performs validation of the specified input type

Method Detail

getEvaluator

PartitioningFunction.Evaluator getEvaluator(PartitioningFunctionContext ctx)

Create an Evaluator bound to the specified context.

Parameters:

ctx - the partitioning context

Returns:

an Evaluator bound to the specified context.

validateForType

void validateForType(RecordTokenType type)

Performs validation of the specified input type

Parameters:

type - the input type

isFunctionOfInput

boolean isFunctionOfInput()

Returns true iff, given two identical rows of input, this function will return the same value. A return of true thus implies :

the function is deterministic the function is stateless (not sensitive to previous values read or to input ordering)

Returns:

whether this function is a stateless, deterministic function of input

isEquivalentPartitioning

boolean isEquivalentPartitioning(PartitioningFunction other)

Returns true iff, given a single row of input, this function is guaranteed to produce the same partitioning as the other function. A return of true thus implies the following:

both functions are deterministic both function are stateless (not sensitive to previous values read or to input ordering) In addition, in order to be consistent with isFunctionOfInput(), this function must return false if isFunctionOfInput() returns false.