org.apache.crunch.lib

Class Sort

java.lang.Object

org.apache.crunch.lib.Sort

public class Sort
extends Object

Utilities for sorting PCollection instances.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Sort.ColumnOrder To sort by column 2 ascending then column 1 descending, you would use: sortPairs(coll, by(2, ASCENDING), by(1, DESCENDING)) Column numbering is 1-based.
static class	Sort.Order For signaling the order in which a sort should be done.

Constructor Summary

Constructors

Constructor and Description
Sort()

Method Summary

Modifier and Type	Method and Description
static <T> PCollection<T>	sort(PCollection<T> collection) Sorts the PCollection using the natural ordering of its elements in ascending order.
static <T> PCollection<T>	sort(PCollection<T> collection, int numReducers, Sort.Order order) Sorts the PCollection using the natural ordering of its elements in the order specified using the given number of reducers.
static <T> PCollection<T>	sort(PCollection<T> collection, Sort.Order order) Sorts the PCollection using the natural order of its elements with the given Order.
static <K,V> PTable<K,V>	sort(PTable<K,V> table) Sorts the PTable using the natural ordering of its keys in ascending order.
static <K,V> PTable<K,V>	sort(PTable<K,V> table, int numReducers, Sort.Order key) Sorts the PTable using the natural ordering of its keys in the order specified with a client-specified number of reducers.
static <K,V> PTable<K,V>	sort(PTable<K,V> table, Sort.Order key) Sorts the PTable using the natural ordering of its keys with the given Order.
static <U,V> PCollection<Pair<U,V>>	sortPairs(PCollection<Pair<U,V>> collection, Sort.ColumnOrder... columnOrders) Sorts the PCollection of Pairs using the specified column ordering.
static <V1,V2,V3,V4> PCollection<Tuple4<V1,V2,V3,V4>>	sortQuads(PCollection<Tuple4<V1,V2,V3,V4>> collection, Sort.ColumnOrder... columnOrders) Sorts the PCollection of Tuple4s using the specified column ordering.
static <V1,V2,V3> PCollection<Tuple3<V1,V2,V3>>	sortTriples(PCollection<Tuple3<V1,V2,V3>> collection, Sort.ColumnOrder... columnOrders) Sorts the PCollection of Tuple3s using the specified column ordering.
static <T extends Tuple> PCollection<T>	sortTuples(PCollection<T> collection, int numReducers, Sort.ColumnOrder... columnOrders) Sorts the PCollection of TupleNs using the specified column ordering and a client-specified number of reducers.
static <T extends Tuple> PCollection<T>	sortTuples(PCollection<T> collection, Sort.ColumnOrder... columnOrders) Sorts the PCollection of tuples using the specified column ordering.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Sort

public Sort()

Method Detail

sort

public static <T> PCollection<T> sort(PCollection<T> collection)

Sorts the PCollection using the natural ordering of its elements in ascending order.

Returns:

a PCollection representing the sorted collection.

sort

public static <T> PCollection<T> sort(PCollection<T> collection,
                                      Sort.Order order)

Sorts the PCollection using the natural order of its elements with the given Order.

Returns:

a PCollection representing the sorted collection.

sort

public static <T> PCollection<T> sort(PCollection<T> collection,
                                      int numReducers,
                                      Sort.Order order)

Sorts the PCollection using the natural ordering of its elements in the order specified using the given number of reducers.

Returns:

a PCollection representing the sorted collection.

sort

public static <K,V> PTable<K,V> sort(PTable<K,V> table)

Sorts the PTable using the natural ordering of its keys in ascending order.

Returns:

a PTable representing the sorted table.

sort

public static <K,V> PTable<K,V> sort(PTable<K,V> table,
                                     Sort.Order key)

Sorts the PTable using the natural ordering of its keys with the given Order.

Returns:

a PTable representing the sorted table.

sort

public static <K,V> PTable<K,V> sort(PTable<K,V> table,
                                     int numReducers,
                                     Sort.Order key)

Sorts the PTable using the natural ordering of its keys in the order specified with a client-specified number of reducers.

Returns:

a PTable representing the sorted collection.

sortPairs

public static <U,V> PCollection<Pair<U,V>> sortPairs(PCollection<Pair<U,V>> collection,
                                                     Sort.ColumnOrder... columnOrders)

Sorts the PCollection of Pairs using the specified column ordering.

Returns:

a PCollection representing the sorted collection.

sortTriples

public static <V1,V2,V3> PCollection<Tuple3<V1,V2,V3>> sortTriples(PCollection<Tuple3<V1,V2,V3>> collection,
                                                                   Sort.ColumnOrder... columnOrders)

Sorts the PCollection of Tuple3s using the specified column ordering.

Returns:

a PCollection representing the sorted collection.

sortQuads

public static <V1,V2,V3,V4> PCollection<Tuple4<V1,V2,V3,V4>> sortQuads(PCollection<Tuple4<V1,V2,V3,V4>> collection,
                                                                       Sort.ColumnOrder... columnOrders)

Sorts the PCollection of Tuple4s using the specified column ordering.

Returns:

a PCollection representing the sorted collection.

sortTuples

public static <T extends Tuple> PCollection<T> sortTuples(PCollection<T> collection,
                                                          Sort.ColumnOrder... columnOrders)

Sorts the PCollection of tuples using the specified column ordering.

Returns:

a PCollection representing the sorted collection.

sortTuples

public static <T extends Tuple> PCollection<T> sortTuples(PCollection<T> collection,
                                                          int numReducers,
                                                          Sort.ColumnOrder... columnOrders)

Sorts the PCollection of TupleNs using the specified column ordering and a client-specified number of reducers.

Returns:

a PCollection representing the sorted collection.