Expert: a MergePolicy determines the sequence of primitive merge operations to be used for overall merge and optimize operations.

Whenever the segments in an index have been altered by {@link IndexWriter}, either the addition of a newly flushed segment, addition of many segments from addIndexes* calls, or a previous merge that may now need to cascade, {@link IndexWriter} invokes {@link #findMerges} to give the MergePolicy a chance to pick merges that are now required. This method returns a {@link MergeSpecification} instance describing the set of merges that should be done, or null if no merges are necessary. When IndexWriter.optimize is called, it calls {@link #findMergesForOptimize} and the MergePolicy should then return the necessary merges.

Note that the policy can return more than one merge at a time. In this case, if the writer is using {@link SerialMergeScheduler}, the merges will be run sequentially but if it is using {@link ConcurrentMergeScheduler} they will be run concurrently.

The default MergePolicy is {@link LogByteSizeMergePolicy}.

NOTE: This API is new and still experimental (subject to change suddenly in the next release)

NOTE: This class typically requires access to package-private APIs (e.g.

CopyC#
SegmentInfos
) to do its job; if you implement your own MergePolicy, you'll need to put it in package Lucene.Net.Index in order to use these APIs.

The MergePolicy..::..MergeSpecification type exposes the following members.

Constructors

  NameDescription
Public methodMergePolicy..::..MergeSpecification
Initializes a new instance of the MergePolicy..::..MergeSpecification class

Methods

  NameDescription
Public methodAdd
Public methodEquals
Determines whether the specified Object is equal to the current Object.
(Inherited from Object.)
Protected methodFinalize
Allows an Object to attempt to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection.
(Inherited from Object.)
Public methodGetHashCode
Serves as a hash function for a particular type.
(Inherited from Object.)
Public methodGetType
Gets the Type of the current instance.
(Inherited from Object.)
Protected methodMemberwiseClone
Creates a shallow copy of the current Object.
(Inherited from Object.)
Public methodSegString
Public methodToString
Returns a String that represents the current Object.
(Inherited from Object.)

Fields

  NameDescription
Public fieldmerges
The subset of segments to be included in the primitive merge.

See Also