Class FilteredQuery.RandomAccessFilterStrategy

A FilteredQuery.FilterStrategy that conditionally uses a random access filter if the given DocIdSet supports random access (returns a non-null value from Bits) and UseRandomAccess(IBits, int) returns

true
. Otherwise this strategy falls back to a "zig-zag join" (

LEAP_FROG_FILTER_FIRST_STRATEGY) strategy .

Inheritance
object
FilteredQuery.FilterStrategy
FilteredQuery.RandomAccessFilterStrategy
Inherited Members
Namespace: Lucene.Net.Search
Assembly: Lucene.Net.dll
Syntax
public class FilteredQuery.RandomAccessFilterStrategy : FilteredQuery.FilterStrategy

Methods

FilteredScorer(AtomicReaderContext, Weight, DocIdSet)

Returns a filtered Scorer based on this strategy.

Declaration
public override Scorer FilteredScorer(AtomicReaderContext context, Weight weight, DocIdSet docIdSet)
Parameters
Type Name Description
AtomicReaderContext context

the AtomicReaderContext for which to return the Scorer.
Weight weight

the FilteredQueryWeight to create the filtered scorer.
DocIdSet docIdSet

the filter DocIdSet to apply
Returns
Type Description
Scorer

a filtered scorer
Overrides
Exceptions
Type Condition
IOException

if an IOException occurs

UseRandomAccess(IBits, int)

Expert: decides if a filter should be executed as "random-access" or not. Random-access means the filter "filters" in a similar way as deleted docs are filtered in Lucene. This is faster when the filter accepts many documents. However, when the filter is very sparse, it can be faster to execute the query+filter as a conjunction in some cases.

The default implementation returns true if the first document accepted by the filter is < 100.

Note

This API is for internal purposes only and might change in incompatible ways in the next release.

Declaration
protected virtual bool UseRandomAccess(IBits bits, int firstFilterDoc)
Parameters
Type Name Description
IBits bits
int firstFilterDoc
Returns
Type Description
bool