public class CoGroup extends Splice implements Group
Joiner.
If followed by an assembly of Everys to execute one or more Aggregators,
they will be guaranteed to receive all values associated with a
unique grouping key. In the case of a MapReduce platform, this invokes a Reduce task to guarantee
all values are associated with a given unique grouping key.
If no aggregations are to be performed, and one or more streams of data are small (may fit in reasonable memory),
see the HashJoin Pipe for partially non-blocking joins.
For every incoming Pipe instance, a Fields instance must be specified that denotes the field names
or positions that should be co-grouped with the other given Pipe instances. If the incoming Pipe instances declare
one or more field with the same name, the declaredFields must be given to name all the outgoing Tuple stream fields
to overcome field name collisions. That is, if the first pipe has 4 fields, and the second pipe has 3 fields, 7 fields
total must be declared having unique field names, if any.
resultGroupFields value is a convenience allowing the override of the resulting grouping field names. The
size of resultGroupFields must be equal to the total number of grouping keys fields. That is, if joining on two pipes
which are grouping on two keys, the resultGroupFields must be 4 fields, each field field name being unique, if any.
By default, the resultGroupKeys are retrieved from the declaredFields.
By default CoGroup performs an inner join via the InnerJoin
Joiner class.
To implement a custom join, implement the Joiner interface. Or, as of Cascading 2.5, use a
BufferJoin and implement the join in a Buffer.
Self joins can be achieved by using a constructor that takes a single Pipe and a numSelfJoins value. A value of 1 for numSelfJoins will join the Pipe with itself once.
The outgoing grouping Tuple stream is sorted by the natural order of the grouping fields. To control this order,
at least the first groupingFields value given should be an instance of Fields containing
Comparator instances for the appropriate fields.
This allows fine grained control of the sort grouping order.
CoGrouping does not scale well when implemented over MapReduce. In Cascading there are two ways to optimize CoGrouping.
The first is to consider the order of the pipes handed to the CoGroup constructor.
During co-grouping, for any given unique grouping key, all of the rightmost pipes will accumulate the current
grouping values into memory so they may be iterated across for every value in the left hand side pipe. During
the accumulation step, if the number of values exceeds the SpillableTupleList threshold
value, those values will be spilled to disk so the accumulation may continue.
See the TupleCollectionFactory and TupleMapFactory for a means
to use alternative spillable types.
There is no accumulation for the left hand side pipe, only for those to the "right".
Thus, for the pipe that has the largest number of values per unique key grouping, on average, it should be made the
"left hand side" pipe (lhs). And all remaining pipes should be the on the "right hand side" (rhs) to
prevent the likelihood of a spill and to reduce the blocking associated with accumulating the values. If using
the Pipe[] constructor, Pipe[0] is the left hand sided pipe.
If spills are happening, consider increasing the spill threshold, see SpillableTupleList,
if more RAM is available. See the logs for hints on how much more these values can be increased, if any.
Spills are intended to prevent OutOfMemoryError's, so reducing the number of spills is important by
increasing the threshold, but memory errors aren't recoverable, so the correct balance will need to be found.
To customize the spill values for a given CoGroup only, see Pipe.getStepConfigDef().
See the Hasher interface when a custom Comparator on the grouping keys is
being provided that makes two values with differing hashCode values equal. For example,
new BigDecimal( 100.0D ) and new Double 100.0D ) are equal using a custom Comparator, but
Object.hashCode() will be different, thus forcing each value into differing partitions.
Currently "non-equi-joins" are not supported via the Hasher and Comparator interfaces. That is, joining one String key with a lowercase value with another String key with an uppercase value using a "case insensitive" Comparator will not have consistent results. The join will execute and be correct, but the actual values in the key columns may be replaced with "equivalent" values from other streams.
If the original key values must be retained, consider normalizing the keys with a Function and then joining on the resulting field.
InnerJoin,
OuterJoin,
LeftJoin,
RightJoin,
MixedJoin,
BufferJoin,
Fields,
SpillableTupleList,
Serialized FormdeclaredFields, keyFieldsMap, resultGroupFields, sortFieldsMapconfigDef, name, nodeConfigDef, parent, previous, stepConfigDef| Constructor and Description |
|---|
CoGroup(Pipe... pipes)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(Pipe[] pipes,
Fields[] groupFields)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(Pipe[] pipes,
Fields[] groupFields,
Fields declaredFields,
Fields resultGroupFields,
Joiner joiner)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(Pipe[] pipes,
Fields[] groupFields,
Fields declaredFields,
Joiner joiner)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(Pipe pipe,
Fields groupFields,
int numSelfJoins)
Constructor CoGroup creates a new CoGroup instance that performs numSelfJoins number of self joins on the
given
Pipe instance. |
CoGroup(Pipe pipe,
Fields groupFields,
int numSelfJoins,
Fields declaredFields)
Constructor CoGroup creates a new CoGroup instance that performs numSelfJoins number of self joins on the
given
Pipe instance. |
CoGroup(Pipe pipe,
Fields groupFields,
int numSelfJoins,
Fields declaredFields,
Fields resultGroupFields)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(Pipe pipe,
Fields groupFields,
int numSelfJoins,
Fields declaredFields,
Fields resultGroupFields,
Joiner joiner)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(Pipe pipe,
Fields groupFields,
int numSelfJoins,
Fields declaredFields,
Joiner joiner)
Constructor CoGroup creates a new CoGroup instance that performs numSelfJoins number of self joins on the
given
Pipe instance. |
CoGroup(Pipe pipe,
Fields groupFields,
int numSelfJoins,
Joiner joiner)
Constructor CoGroup creates a new CoGroup instance that performs numSelfJoins number of self joins on the
given
Pipe instance. |
CoGroup(Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Fields declaredFields)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Fields declaredFields,
Fields resultGroupFields)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Fields declaredFields,
Fields resultGroupFields,
Joiner joiner)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Fields declaredFields,
Joiner joiner)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Joiner joiner)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(java.lang.String groupName,
Pipe... pipes)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(java.lang.String groupName,
Pipe[] pipes,
Fields[] groupFields)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(java.lang.String groupName,
Pipe[] pipes,
Fields[] groupFields,
Fields declaredFields)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(java.lang.String groupName,
Pipe[] pipes,
Fields[] groupFields,
Fields declaredFields,
Fields resultGroupFields)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(java.lang.String groupName,
Pipe[] pipes,
Fields[] groupFields,
Fields declaredFields,
Fields resultGroupFields,
Joiner joiner)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(java.lang.String groupName,
Pipe[] pipes,
Fields[] groupFields,
Fields declaredFields,
Joiner joiner)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(java.lang.String groupName,
Pipe pipe,
Fields groupFields,
int numSelfJoins)
Constructor CoGroup creates a new CoGroup instance that performs numSelfJoins number of self joins on the
given
Pipe instance. |
CoGroup(java.lang.String groupName,
Pipe pipe,
Fields groupFields,
int numSelfJoins,
Fields declaredFields)
Constructor CoGroup creates a new CoGroup instance that performs numSelfJoins number of self joins on the
given
Pipe instance. |
CoGroup(java.lang.String groupName,
Pipe pipe,
Fields groupFields,
int numSelfJoins,
Fields declaredFields,
Fields resultGroupFields)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(java.lang.String groupName,
Pipe pipe,
Fields groupFields,
int numSelfJoins,
Fields declaredFields,
Fields resultGroupFields,
Joiner joiner)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(java.lang.String groupName,
Pipe pipe,
Fields groupFields,
int numSelfJoins,
Fields declaredFields,
Joiner joiner)
Constructor CoGroup creates a new CoGroup instance that performs numSelfJoins number of self joins on the
given
Pipe instance. |
CoGroup(java.lang.String groupName,
Pipe pipe,
Fields groupFields,
int numSelfJoins,
Joiner joiner)
Constructor CoGroup creates a new CoGroup instance that performs numSelfJoins number of self joins on the
given
Pipe instance. |
CoGroup(java.lang.String groupName,
Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(java.lang.String groupName,
Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Fields declaredFields)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(java.lang.String groupName,
Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Fields declaredFields,
Fields resultGroupFields)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(java.lang.String groupName,
Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Fields declaredFields,
Fields resultGroupFields,
Joiner joiner)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(java.lang.String groupName,
Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Fields declaredFields,
Joiner joiner)
Constructor CoGroup creates a new CoGroup instance.
|
CoGroup(java.lang.String groupName,
Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Joiner joiner)
Constructor CoGroup creates a new CoGroup instance.
|
equals, getDeclaredFields, getJoinDeclaredFields, getJoiner, getKeySelectors, getName, getNumSelfJoins, getPipePos, getPrevious, getSortingSelectors, hashCode, isCoGroup, isGroupBy, isJoin, isMerge, isSelfJoin, isSorted, isSortReversed, outgoingScopeFor, printInternal, resolveIncomingOperationPassThroughFields, toStringgetConfigDef, getHeads, getNodeConfigDef, getParent, getStepConfigDef, getTrace, hasConfigDef, hasNodeConfigDef, hasStepConfigDef, id, named, names, pipes, print, resolveIncomingOperationArgumentFields, setParentclone, finalize, getClass, notify, notifyAll, wait, wait, waitgetKeySelectors, getName, getSortingSelectors, isCoGroup, isGroupBy, isSorted, isSortReversed@ConstructorProperties(value={"lhs","lhsGroupFields","rhs","rhsGroupFields","declaredFields"})
public CoGroup(Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Fields declaredFields)
lhs - of type PipelhsGroupFields - of type Fieldsrhs - of type PiperhsGroupFields - of type FieldsdeclaredFields - of type Fields@ConstructorProperties(value={"lhs","lhsGroupFields","rhs","rhsGroupFields","declaredFields","resultGroupFields"})
public CoGroup(Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Fields declaredFields,
Fields resultGroupFields)
lhs - of type PipelhsGroupFields - of type Fieldsrhs - of type PiperhsGroupFields - of type FieldsdeclaredFields - of type FieldsresultGroupFields - of type Fields@ConstructorProperties(value={"lhs","lhsGroupFields","rhs","rhsGroupFields","declaredFields","joiner"})
public CoGroup(Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Fields declaredFields,
Joiner joiner)
lhs - of type PipelhsGroupFields - of type Fieldsrhs - of type PiperhsGroupFields - of type FieldsdeclaredFields - of type Fieldsjoiner - of type CoGrouper@ConstructorProperties(value={"lhs","lhsGroupFields","rhs","rhsGroupFields","declaredFields","resultGroupFields","joiner"})
public CoGroup(Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Fields declaredFields,
Fields resultGroupFields,
Joiner joiner)
lhs - of type PipelhsGroupFields - of type Fieldsrhs - of type PiperhsGroupFields - of type FieldsdeclaredFields - of type FieldsresultGroupFields - of type Fieldsjoiner - of type Joiner@ConstructorProperties(value={"lhs","lhsGroupFields","rhs","rhsGroupFields","joiner"})
public CoGroup(Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Joiner joiner)
lhs - of type PipelhsGroupFields - of type Fieldsrhs - of type PiperhsGroupFields - of type Fieldsjoiner - of type CoGrouper@ConstructorProperties(value={"lhs","lhsGroupFields","rhs","rhsGroupFields"})
public CoGroup(Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields)
lhs - of type PipelhsGroupFields - of type Fieldsrhs - of type PiperhsGroupFields - of type Fields@ConstructorProperties(value="pipes") public CoGroup(Pipe... pipes)
pipes - of type Pipe...@ConstructorProperties(value={"pipes","groupFields"})
public CoGroup(Pipe[] pipes,
Fields[] groupFields)
pipes - of type Pipe[]groupFields - of type Fields[]@ConstructorProperties(value={"pipes","groupFields","declaredFields","joiner"})
public CoGroup(Pipe[] pipes,
Fields[] groupFields,
Fields declaredFields,
Joiner joiner)
pipes - of type Pipe[]groupFields - of type Fields[]declaredFields - of type Fieldsjoiner - of type CoGrouper@ConstructorProperties(value={"pipes","groupFields","declaredFields","resultGroupFields","joiner"})
public CoGroup(Pipe[] pipes,
Fields[] groupFields,
Fields declaredFields,
Fields resultGroupFields,
Joiner joiner)
pipes - of type Pipe[]groupFields - of type Fields[]declaredFields - of type FieldsresultGroupFields - of type Fieldsjoiner - of type Joiner@ConstructorProperties(value={"groupName","pipes","groupFields"})
public CoGroup(java.lang.String groupName,
Pipe[] pipes,
Fields[] groupFields)
groupName - of type Stringpipes - of type Pipe[]groupFields - of type Fields[]@ConstructorProperties(value={"groupName","pipes","groupFields","declaredFields"})
public CoGroup(java.lang.String groupName,
Pipe[] pipes,
Fields[] groupFields,
Fields declaredFields)
groupName - of type Stringpipes - of type Pipe[]groupFields - of type Fields[]declaredFields - of type Fields@ConstructorProperties(value={"groupName","pipes","groupFields","declaredFields","resultGroupFields"})
public CoGroup(java.lang.String groupName,
Pipe[] pipes,
Fields[] groupFields,
Fields declaredFields,
Fields resultGroupFields)
groupName - of type Stringpipes - of type Pipe[]groupFields - of type Fields[]declaredFields - of type FieldsresultGroupFields - of type Fields@ConstructorProperties(value={"groupName","pipes","groupFields","declaredFields","joiner"})
public CoGroup(java.lang.String groupName,
Pipe[] pipes,
Fields[] groupFields,
Fields declaredFields,
Joiner joiner)
groupName - of type Stringpipes - of type Pipe[]groupFields - of type Fields[]declaredFields - of type Fieldsjoiner - of type CoGrouper@ConstructorProperties(value={"groupName","pipes","groupFields","declaredFields","resultGroupFields","joiner"})
public CoGroup(java.lang.String groupName,
Pipe[] pipes,
Fields[] groupFields,
Fields declaredFields,
Fields resultGroupFields,
Joiner joiner)
groupName - of type Stringpipes - of type Pipe[]groupFields - of type Fields[]declaredFields - of type FieldsresultGroupFields - of type Fieldsjoiner - of type CoGrouper@ConstructorProperties(value={"groupName","lhs","lhsGroupFields","rhs","rhsGroupFields","declaredFields"})
public CoGroup(java.lang.String groupName,
Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Fields declaredFields)
groupName - of type Stringlhs - of type PipelhsGroupFields - of type Fieldsrhs - of type PiperhsGroupFields - of type FieldsdeclaredFields - of type Fields@ConstructorProperties(value={"groupName","lhs","lhsGroupFields","rhs","rhsGroupFields","declaredFields","resultGroupFields"})
public CoGroup(java.lang.String groupName,
Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Fields declaredFields,
Fields resultGroupFields)
groupName - of type Stringlhs - of type PipelhsGroupFields - of type Fieldsrhs - of type PiperhsGroupFields - of type FieldsdeclaredFields - of type FieldsresultGroupFields - of type Fields@ConstructorProperties(value={"groupName","lhs","lhsGroupFields","rhs","rhsGroupFields","declaredFields","joiner"})
public CoGroup(java.lang.String groupName,
Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Fields declaredFields,
Joiner joiner)
groupName - of type Stringlhs - of type PipelhsGroupFields - of type Fieldsrhs - of type PiperhsGroupFields - of type FieldsdeclaredFields - of type Fieldsjoiner - of type CoGrouper@ConstructorProperties(value={"groupName","lhs","lhsGroupFields","rhs","rhsGroupFields","declaredFields","resultGroupFields","joiner"})
public CoGroup(java.lang.String groupName,
Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Fields declaredFields,
Fields resultGroupFields,
Joiner joiner)
groupName - of type Stringlhs - of type PipelhsGroupFields - of type Fieldsrhs - of type PiperhsGroupFields - of type FieldsdeclaredFields - of type FieldsresultGroupFields - of type Fieldsjoiner - of type Joiner@ConstructorProperties(value={"groupName","lhs","lhsGroupFields","rhs","rhsGroupFields","joiner"})
public CoGroup(java.lang.String groupName,
Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields,
Joiner joiner)
groupName - of type Stringlhs - of type PipelhsGroupFields - of type Fieldsrhs - of type PiperhsGroupFields - of type Fieldsjoiner - of type CoGrouper@ConstructorProperties(value={"groupName","lhs","lhsGroupFields","rhs","rhsGroupFields"})
public CoGroup(java.lang.String groupName,
Pipe lhs,
Fields lhsGroupFields,
Pipe rhs,
Fields rhsGroupFields)
groupName - of type Stringlhs - of type PipelhsGroupFields - of type Fieldsrhs - of type PiperhsGroupFields - of type Fields@ConstructorProperties(value={"groupName","pipes"})
public CoGroup(java.lang.String groupName,
Pipe... pipes)
groupName - of type Stringpipes - of type Pipe...@ConstructorProperties(value={"pipe","groupFields","numSelfJoins","declaredFields"})
public CoGroup(Pipe pipe,
Fields groupFields,
int numSelfJoins,
Fields declaredFields)
Pipe instance.pipe - of type PipegroupFields - of type FieldsnumSelfJoins - of type intdeclaredFields - of type Fields@ConstructorProperties(value={"pipe","groupFields","numSelfJoins","declaredFields","resultGroupFields"})
public CoGroup(Pipe pipe,
Fields groupFields,
int numSelfJoins,
Fields declaredFields,
Fields resultGroupFields)
pipe - of type PipegroupFields - of type FieldsnumSelfJoins - of type intdeclaredFields - of type FieldsresultGroupFields - of type Fields@ConstructorProperties(value={"pipe","groupFields","numSelfJoins","declaredFields","joiner"})
public CoGroup(Pipe pipe,
Fields groupFields,
int numSelfJoins,
Fields declaredFields,
Joiner joiner)
Pipe instance.pipe - of type PipegroupFields - of type FieldsnumSelfJoins - of type intdeclaredFields - of type Fieldsjoiner - of type CoGrouper@ConstructorProperties(value={"pipe","groupFields","numSelfJoins","declaredFields","resultGroupFields","joiner"})
public CoGroup(Pipe pipe,
Fields groupFields,
int numSelfJoins,
Fields declaredFields,
Fields resultGroupFields,
Joiner joiner)
pipe - of type PipegroupFields - of type FieldsnumSelfJoins - of type intdeclaredFields - of type FieldsresultGroupFields - of type Fieldsjoiner - of type Joiner@ConstructorProperties(value={"pipe","groupFields","numSelfJoins","joiner"})
public CoGroup(Pipe pipe,
Fields groupFields,
int numSelfJoins,
Joiner joiner)
Pipe instance.pipe - of type PipegroupFields - of type FieldsnumSelfJoins - of type intjoiner - of type CoGrouper@ConstructorProperties(value={"pipe","groupFields","numSelfJoins"})
public CoGroup(Pipe pipe,
Fields groupFields,
int numSelfJoins)
Pipe instance.pipe - of type PipegroupFields - of type FieldsnumSelfJoins - of type int@ConstructorProperties(value={"groupName","pipe","groupFields","numSelfJoins","declaredFields"})
public CoGroup(java.lang.String groupName,
Pipe pipe,
Fields groupFields,
int numSelfJoins,
Fields declaredFields)
Pipe instance.groupName - of type Stringpipe - of type PipegroupFields - of type FieldsnumSelfJoins - of type intdeclaredFields - of type Fields@ConstructorProperties(value={"groupName","pipe","groupFields","numSelfJoins","declaredFields","resultGroupFields"})
public CoGroup(java.lang.String groupName,
Pipe pipe,
Fields groupFields,
int numSelfJoins,
Fields declaredFields,
Fields resultGroupFields)
groupName - of type Stringpipe - of type PipegroupFields - of type FieldsnumSelfJoins - of type intdeclaredFields - of type FieldsresultGroupFields - of type Fields@ConstructorProperties(value={"groupName","pipe","groupFields","numSelfJoins","declaredFields","joiner"})
public CoGroup(java.lang.String groupName,
Pipe pipe,
Fields groupFields,
int numSelfJoins,
Fields declaredFields,
Joiner joiner)
Pipe instance.groupName - of type Stringpipe - of type PipegroupFields - of type FieldsnumSelfJoins - of type intdeclaredFields - of type Fieldsjoiner - of type CoGrouper@ConstructorProperties(value={"groupName","pipe","groupFields","numSelfJoins","declaredFields","resultGroupFields","joiner"})
public CoGroup(java.lang.String groupName,
Pipe pipe,
Fields groupFields,
int numSelfJoins,
Fields declaredFields,
Fields resultGroupFields,
Joiner joiner)
groupName - of type Stringpipe - of type PipegroupFields - of type FieldsnumSelfJoins - of type intdeclaredFields - of type FieldsresultGroupFields - of type Fieldsjoiner - of type Joiner@ConstructorProperties(value={"groupName","pipe","groupFields","numSelfJoins","joiner"})
public CoGroup(java.lang.String groupName,
Pipe pipe,
Fields groupFields,
int numSelfJoins,
Joiner joiner)
Pipe instance.groupName - of type Stringpipe - of type PipegroupFields - of type FieldsnumSelfJoins - of type intjoiner - of type CoGrouper@ConstructorProperties(value={"groupName","pipe","groupFields","numSelfJoins"})
public CoGroup(java.lang.String groupName,
Pipe pipe,
Fields groupFields,
int numSelfJoins)
Pipe instance.groupName - of type Stringpipe - of type PipegroupFields - of type FieldsnumSelfJoins - of type intCopyright © 2007-2017 Cascading Maintainers. All Rights Reserved.