public interface Joiner extends java.io.Serializable
CoGroup
.
Joins perform based on the equality of the join keys. In the case of null values, Java treats two
null values as equivalent. SQL does not treat null values as equal. To produce SQL like results in a given
join, a new Comparator
will need to be used on the joined values to prevent null from
equaling null. As a convenience, see the NullNotEquivalentComparator
class.
Modifier and Type | Method and Description |
---|---|
java.util.Iterator<Tuple> |
getIterator(JoinerClosure closure)
Returns an iterator that joins the given CoGroupClosure co-groups.
|
int |
numJoins()
Returns the number of joins this instance can handle.
|
java.util.Iterator<Tuple> getIterator(JoinerClosure closure)
closure
- of type GroupClosureint numJoins()
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