List of all members.
If the set of entries is empty, an empty set is returned.
This aggregator could be used in combination with coherence::util::extractor::MultiExtractor allowing to collect all unique combinations (tuples) of a given set of attributes.
The DistinctValues aggregator covers a simple case of a more generic aggregation pattern implemented by the GroupAggregator, which in addition to collecting all distinct values or tuples, runs an aggregation against each distinct entry set (group).
|DistinctValues Handle definition. |
|DistinctValues View definition. |
|DistinctValues Holder definition. |
Protected Member Functions
|Default constructor (necessary for the PortableObject interface). |
|DistinctValues (ValueExtractor::View vExtractor)|
|Construct a DistinceValues aggregator. |
|virtual void||init (bool fFinal)|
|Initialize the aggregation result.|
|virtual void||process (Object::View vO, bool fFinal)|
|Incorporate one aggregatable value into the result.|
|virtual Object::Holder||finalizeResult (bool fFinal)|
|Obtain the result of the aggregation.|
|virtual Set::Handle||ensureSet ()|
|Return a set that can be used to store distinct values, creating it if one has not already been created. |
|MemberHandle< Set >||m_hSet|
|The resulting set of distinct values. |
|virtual Set::Handle ensureSet||(||)||
Return a set that can be used to store distinct values, creating it if one has not already been created.