public class Union
extends org.apache.pig.EvalFunc<org.apache.pig.data.Tuple>
implements org.apache.pig.Accumulator<org.apache.pig.data.Tuple>, org.apache.pig.Algebraic
Modifier and Type | Class and Description |
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static class |
Union.Initial
Class used to calculate the initial pass of an Algebraic sketch operation.
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static class |
Union.IntermediateFinal
Class used to calculate the intermediate or final combiner pass of an Algebraic union
operation.
|
Constructor and Description |
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Union()
Default constructor to make pig validation happy.
|
Union(int nomEntries,
float p,
long seed)
Base constructor.
|
Union(String nomEntriesStr)
String constructor.
|
Union(String nomEntriesStr,
String pStr)
String constructor.
|
Union(String nomEntriesStr,
String pStr,
String seedStr)
Full string constructor.
|
Modifier and Type | Method and Description |
---|---|
void |
accumulate(org.apache.pig.data.Tuple inputTuple)
An Accumulator version of the standard exec() method.
|
void |
cleanup()
Cleans up the UDF state after being called using the
Accumulator interface. |
org.apache.pig.data.Tuple |
exec(org.apache.pig.data.Tuple inputTuple)
Top-level exec function.
|
String |
getFinal() |
String |
getInitial() |
String |
getIntermed() |
org.apache.pig.data.Tuple |
getValue()
Returns the sketch that has been built up by multiple calls to
accumulate(org.apache.pig.data.Tuple) . |
org.apache.pig.impl.logicalLayer.schema.Schema |
outputSchema(org.apache.pig.impl.logicalLayer.schema.Schema input) |
allowCompileTimeCalculation, finish, getArgToFuncMapping, getCacheFiles, getInputSchema, getLoadCaster, getLogger, getPigLogger, getReporter, getReturnType, getSchemaName, getSchemaType, getShipFiles, isAsynchronous, needEndOfAllInputProcessing, progress, setEndOfAllInput, setInputSchema, setPigLogger, setReporter, setUDFContextSignature, warn
public Union()
public Union(String nomEntriesStr)
nomEntriesStr
- See Nominal Entriespublic Union(String nomEntriesStr, String pStr)
nomEntriesStr
- See Nominal EntriespStr
- See Sampling Probability, p.
Although this functionality is implemented for SketchUnions, it rarely makes sense to use it
here. The proper use of upfront sampling is when building the sketches.public Union(String nomEntriesStr, String pStr, String seedStr)
nomEntriesStr
- See Nominal Entries.pStr
- See Sampling Probability, p.
Although this functionality is implemented for SketchUnions, it rarely makes sense to use it
here. The proper use of upfront sampling is when building the sketches.seedStr
- See Update Hash Seed.public Union(int nomEntries, float p, long seed)
nomEntries
- See Nominal Entries.p
- See Sampling Probability, p.
Although this functionality is implemented for SketchUnions, it rarely makes sense to use it
here. The proper use of upfront sampling is when building the sketches.seed
- See Update Hash Seed.public org.apache.pig.data.Tuple exec(org.apache.pig.data.Tuple inputTuple) throws IOException
If a large number of calls are anticipated, leveraging either the Algebraic or Accumulator interfaces is recommended. Pig normally handles this automatically.
Internally, this method presents the inner Sketch Tuples to a new Union. The result is returned as a Sketch Tuple
Input Tuple
exec
in class org.apache.pig.EvalFunc<org.apache.pig.data.Tuple>
inputTuple
- A tuple containing a single bag, containing Sketch Tuples.IOException
public org.apache.pig.impl.logicalLayer.schema.Schema outputSchema(org.apache.pig.impl.logicalLayer.schema.Schema input)
outputSchema
in class org.apache.pig.EvalFunc<org.apache.pig.data.Tuple>
public void accumulate(org.apache.pig.data.Tuple inputTuple) throws IOException
accumulate
in interface org.apache.pig.Accumulator<org.apache.pig.data.Tuple>
inputTuple
- A tuple containing a single bag, containing Sketch Tuples.IOException
- by Pigexec(org.apache.pig.data.Tuple)
,
"org.apache.pig.Accumulator.accumulate(org.apache.pig.data.Tuple)"public org.apache.pig.data.Tuple getValue()
accumulate(org.apache.pig.data.Tuple)
.getValue
in interface org.apache.pig.Accumulator<org.apache.pig.data.Tuple>
exec(org.apache.pig.data.Tuple)
for return tuple format)public void cleanup()
Accumulator
interface.cleanup
in interface org.apache.pig.Accumulator<org.apache.pig.data.Tuple>
public String getInitial()
getInitial
in interface org.apache.pig.Algebraic
public String getIntermed()
getIntermed
in interface org.apache.pig.Algebraic
public String getFinal()
getFinal
in interface org.apache.pig.Algebraic
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