Package org.apache.lucene.index.sorter

Provides index sorting capablities. The application can use one of the pre-existing Sorter implementations, e.g. to sort by a NumericDocValuesSorter or reverse the order of the documents. Additionally, the application can implement a custom Sorter which returns a permutation on a source AtomicReader's document IDs, to sort the input documents by additional criteria.

SortingMergePolicy can be used to make Lucene sort segments before merging them. This will ensure that every segment resulting from a merge will be sorted according to the provided Sorter. This however makes merging and thus indexing slower.

Sorted segments allow for early query termination when the sort order matches index order. This makes query execution faster since not all documents need to be visited. Please note that this is an expert feature and should not be used without a deep understanding of Lucene merging and document collection.

Class Summary

Class	Description
BlockJoinSorter	Helper class to sort readers that contain blocks of documents.
EarlyTerminatingSortingCollector	A Collector that early terminates collection of documents on a per-segment basis, if the segment was sorted according to the given Sorter.
NumericDocValuesSorter	A Sorter which sorts documents according to their NumericDocValues.
Sorter	Sorts documents of a given index by returning a permutation on the document IDs.
Sorter.DocComparator	A comparator of doc IDs.
Sorter.DocMap	A permutation of doc IDs.
SortingAtomicReader	An AtomicReader which supports sorting documents by a given Sorter.
SortingMergePolicy	A MergePolicy that reorders documents according to a Sorter before merging them.