This project has retired. For details please refer to its Attic page.
Cogroup (Apache Crunch 0.8.0 API)

org.apache.crunch.lib
Class Cogroup

java.lang.Object
  extended by org.apache.crunch.lib.Cogroup

public class Cogroup
extends Object


Constructor Summary
Cogroup()
           
 
Method Summary
static
<K,U,V> PTable<K,TupleN>
cogroup(int numReducers, PTable<K,?> first, PTable<K,?>... rest)
          Co-groups an arbitrary number of PTable arguments with a user-specified degree of parallelism (a.k.a, number of reducers.) The largest table should come last in the ordering.
static
<K,U,V> PTable<K,Pair<Collection<U>,Collection<V>>>
cogroup(int numReducers, PTable<K,U> left, PTable<K,V> right)
          Co-groups the two PTable arguments with a user-specified degree of parallelism (a.k.a, number of reducers.)
static
<K,V1,V2,V3>
PTable<K,Tuple3.Collect<V1,V2,V3>>
cogroup(int numReducers, PTable<K,V1> first, PTable<K,V2> second, PTable<K,V3> third)
          Co-groups the three PTable arguments with a user-specified degree of parallelism (a.k.a, number of reducers.)
static
<K,V1,V2,V3,V4>
PTable<K,Tuple4.Collect<V1,V2,V3,V4>>
cogroup(int numReducers, PTable<K,V1> first, PTable<K,V2> second, PTable<K,V3> third, PTable<K,V4> fourth)
          Co-groups the three PTable arguments with a user-specified degree of parallelism (a.k.a, number of reducers.)
static
<K> PTable<K,TupleN>
cogroup(PTable<K,?> first, PTable<K,?>... rest)
          Co-groups an arbitrary number of PTable arguments.
static
<K,U,V> PTable<K,Pair<Collection<U>,Collection<V>>>
cogroup(PTable<K,U> left, PTable<K,V> right)
          Co-groups the two PTable arguments.
static
<K,V1,V2,V3>
PTable<K,Tuple3.Collect<V1,V2,V3>>
cogroup(PTable<K,V1> first, PTable<K,V2> second, PTable<K,V3> third)
          Co-groups the three PTable arguments.
static
<K,V1,V2,V3,V4>
PTable<K,Tuple4.Collect<V1,V2,V3,V4>>
cogroup(PTable<K,V1> first, PTable<K,V2> second, PTable<K,V3> third, PTable<K,V4> fourth)
          Co-groups the three PTable arguments.
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Cogroup

public Cogroup()
Method Detail

cogroup

public static <K,U,V> PTable<K,Pair<Collection<U>,Collection<V>>> cogroup(PTable<K,U> left,
                                                                          PTable<K,V> right)
Co-groups the two PTable arguments.

Parameters:
left - The left (smaller) PTable
right - The right (larger) PTable
Returns:
a PTable representing the co-grouped tables

cogroup

public static <K,U,V> PTable<K,Pair<Collection<U>,Collection<V>>> cogroup(int numReducers,
                                                                          PTable<K,U> left,
                                                                          PTable<K,V> right)
Co-groups the two PTable arguments with a user-specified degree of parallelism (a.k.a, number of reducers.)

Parameters:
numReducers - The number of reducers to use
left - The left (smaller) PTable
right - The right (larger) PTable
Returns:
A new PTable representing the co-grouped tables

cogroup

public static <K,V1,V2,V3> PTable<K,Tuple3.Collect<V1,V2,V3>> cogroup(PTable<K,V1> first,
                                                                      PTable<K,V2> second,
                                                                      PTable<K,V3> third)
Co-groups the three PTable arguments.

Parameters:
first - The smallest PTable
second - The second-smallest PTable
third - The largest PTable
Returns:
a PTable representing the co-grouped tables

cogroup

public static <K,V1,V2,V3> PTable<K,Tuple3.Collect<V1,V2,V3>> cogroup(int numReducers,
                                                                      PTable<K,V1> first,
                                                                      PTable<K,V2> second,
                                                                      PTable<K,V3> third)
Co-groups the three PTable arguments with a user-specified degree of parallelism (a.k.a, number of reducers.)

Parameters:
numReducers - The number of reducers to use
first - The smallest PTable
second - The second-smallest PTable
third - The largest PTable
Returns:
A new PTable representing the co-grouped tables

cogroup

public static <K,V1,V2,V3,V4> PTable<K,Tuple4.Collect<V1,V2,V3,V4>> cogroup(PTable<K,V1> first,
                                                                            PTable<K,V2> second,
                                                                            PTable<K,V3> third,
                                                                            PTable<K,V4> fourth)
Co-groups the three PTable arguments.

Parameters:
first - The smallest PTable
second - The second-smallest PTable
third - The largest PTable
Returns:
a PTable representing the co-grouped tables

cogroup

public static <K,V1,V2,V3,V4> PTable<K,Tuple4.Collect<V1,V2,V3,V4>> cogroup(int numReducers,
                                                                            PTable<K,V1> first,
                                                                            PTable<K,V2> second,
                                                                            PTable<K,V3> third,
                                                                            PTable<K,V4> fourth)
Co-groups the three PTable arguments with a user-specified degree of parallelism (a.k.a, number of reducers.)

Parameters:
numReducers - The number of reducers to use
first - The smallest PTable
second - The second-smallest PTable
third - The largest PTable
Returns:
A new PTable representing the co-grouped tables

cogroup

public static <K> PTable<K,TupleN> cogroup(PTable<K,?> first,
                                           PTable<K,?>... rest)
Co-groups an arbitrary number of PTable arguments. The largest table should come last in the ordering.

Parameters:
first - The first (smallest) PTable to co-group
rest - The other (larger) PTables to co-group
Returns:
a PTable representing the co-grouped tables

cogroup

public static <K,U,V> PTable<K,TupleN> cogroup(int numReducers,
                                               PTable<K,?> first,
                                               PTable<K,?>... rest)
Co-groups an arbitrary number of PTable arguments with a user-specified degree of parallelism (a.k.a, number of reducers.) The largest table should come last in the ordering.

Parameters:
numReducers - The number of reducers to use
first - The first (smallest) PTable to co-group
rest - The other (larger) PTables to co-group
Returns:
A new PTable representing the co-grouped tables


Copyright © 2013 The Apache Software Foundation. All Rights Reserved.