Method Open

Open(Directory)

Returns a IndexReader reading the index in the given Directory

Declaration
public static DirectoryReader Open(Directory directory)
Parameters
Type Name Description
Directory directory

the index directory

Returns
Type Description
DirectoryReader

Open(Directory, Int32)

Expert: Returns a IndexReader reading the index in the given Directory with the given termInfosIndexDivisor.

Declaration
public static DirectoryReader Open(Directory directory, int termInfosIndexDivisor)
Parameters
Type Name Description
Directory directory

the index directory

System.Int32 termInfosIndexDivisor

Subsamples which indexed terms are loaded into RAM. this has the same effect as setting TermIndexInterval (on IndexWriterConfig) except that setting must be done at indexing time while this setting can be set per reader. When set to N, then one in every N*termIndexInterval terms in the index is loaded into memory. By setting this to a value > 1 you can reduce memory usage, at the expense of higher latency when loading a TermInfo. The default value is 1. Set this to -1 to skip loading the terms index entirely. NOTE: divisor settings > 1 do not apply to all PostingsFormat implementations, including the default one in this release. It only makes sense for terms indexes that can efficiently re-sample terms at load time.

Returns
Type Description
DirectoryReader

Open(IndexWriter, Boolean)

Open a near real time IndexReader from the IndexWriter.

@lucene.experimental

Declaration
public static DirectoryReader Open(IndexWriter writer, bool applyAllDeletes)
Parameters
Type Name Description
IndexWriter writer

The IndexWriter to open from

System.Boolean applyAllDeletes

If true, all buffered deletes will be applied (made visible) in the returned reader. If false, the deletes are not applied but remain buffered (in IndexWriter) so that they will be applied in the future. Applying deletes can be costly, so if your app can tolerate deleted documents being returned you might gain some performance by passing false.

Returns
Type Description
DirectoryReader

The new IndexReader

Exceptions
Type Condition
CorruptIndexException

if the index is corrupt

See Also

Open(IndexCommit)

Expert: returns an IndexReader reading the index in the given IndexCommit.

Declaration
public static DirectoryReader Open(IndexCommit commit)
Parameters
Type Name Description
IndexCommit commit

the commit point to open

Returns
Type Description
DirectoryReader

Open(IndexCommit, Int32)

Expert: returns an IndexReader reading the index in the given IndexCommit and termInfosIndexDivisor.

Declaration
public static DirectoryReader Open(IndexCommit commit, int termInfosIndexDivisor)
Parameters
Type Name Description
IndexCommit commit

the commit point to open

System.Int32 termInfosIndexDivisor

Subsamples which indexed terms are loaded into RAM. this has the same effect as setting TermIndexInterval (on IndexWriterConfig) except that setting must be done at indexing time while this setting can be set per reader. When set to N, then one in every N*termIndexInterval terms in the index is loaded into memory. By setting this to a value > 1 you can reduce memory usage, at the expense of higher latency when loading a TermInfo. The default value is 1. Set this to -1 to skip loading the terms index entirely. NOTE: divisor settings > 1 do not apply to all PostingsFormat implementations, including the default one in this release. It only makes sense for terms indexes that can efficiently re-sample terms at load time.

Returns
Type Description
DirectoryReader