org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators
Class POFilter
java.lang.Object
org.apache.pig.impl.plan.Operator<PhyPlanVisitor>
org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator
org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POFilter
- All Implemented Interfaces:
- Serializable, Cloneable, Comparable<Operator>, Illustrable
public class POFilter
- extends PhysicalOperator
This is an implementation of the Filter operator. It has an Expression Plan
that decides whether the input tuple should be filtered or passed through. To
avoid many function calls, the filter operator, stores the Comparison
Operator that is the root of the Expression Plan and uses its getNext
directly.
Since the filter is supposed to return tuples only, getNext is not supported
on any other data type.
- See Also:
- Serialized Form
Fields inherited from class org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator |
alias, dummyBag, dummyBool, dummyDBA, dummyDouble, dummyFloat, dummyInt, dummyLong, dummyMap, dummyString, dummyTuple, illustrator, input, inputAttached, inputs, lineageTracer, outputs, parentPlan, pigLogger, reporter, requestedParallelism, res, resultType |
Fields inherited from class org.apache.pig.impl.plan.Operator |
mKey |
Methods inherited from class org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator |
attachInput, clone, cloneHelper, detachInput, getAlias, getAliasString, getDummy, getIllustrator, getInputs, getLogger, getNext, getNext, getNext, getNext, getNext, getNext, getNext, getNext, getNext, getNext, getPigLogger, getRequestedParallelism, getResultType, isAccumStarted, isAccumulative, isBlocking, isInputAttached, processInput, reset, setAccumEnd, setAccumStart, setAccumulative, setAlias, setIllustrator, setInputs, setParentPlan, setPigLogger, setReporter, setRequestedParallelism, setResultType |
POFilter
public POFilter(OperatorKey k)
POFilter
public POFilter(OperatorKey k,
int rp)
POFilter
public POFilter(OperatorKey k,
List<PhysicalOperator> inputs)
POFilter
public POFilter(OperatorKey k,
int rp,
List<PhysicalOperator> inputs)
getNext
public Result getNext(Tuple t)
throws ExecException
- Attaches the proccesed input tuple to the expression plan and checks if
comparison operator returns a true. If so the tuple is not filtered and
let to pass through. Else, further input is processed till a tuple that
can be passed through is found or EOP is reached.
- Overrides:
getNext
in class PhysicalOperator
- Throws:
ExecException
name
public String name()
- Specified by:
name
in class Operator<PhyPlanVisitor>
supportsMultipleInputs
public boolean supportsMultipleInputs()
- Description copied from class:
Operator
- Indicates whether this operator supports multiple inputs.
- Specified by:
supportsMultipleInputs
in class Operator<PhyPlanVisitor>
- Returns:
- true if it does, otherwise false.
supportsMultipleOutputs
public boolean supportsMultipleOutputs()
- Description copied from class:
Operator
- Indicates whether this operator supports multiple outputs.
- Specified by:
supportsMultipleOutputs
in class Operator<PhyPlanVisitor>
- Returns:
- true if it does, otherwise false.
visit
public void visit(PhyPlanVisitor v)
throws VisitorException
- Description copied from class:
Operator
- Visit this node with the provided visitor. This should only be called by
the visitor class itself, never directly.
- Specified by:
visit
in class PhysicalOperator
- Parameters:
v
- Visitor to visit with.
- Throws:
VisitorException
- if the visitor has a problem.
setPlan
public void setPlan(PhysicalPlan plan)
getPlan
public PhysicalPlan getPlan()
illustratorMarkup
public Tuple illustratorMarkup(Object in,
Object out,
int eqClassIndex)
- Description copied from interface:
Illustrable
- input tuple mark up to be illustrate-able
- Parameters:
in
- input tupleout
- output tuple before wrapped in ExampleTupleeqClassIndex
- index into equivalence classes in illustrator
- Returns:
- tuple
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