Class IndexWriterConfig

Holds all the configuration that is used to create an IndexWriter. Once IndexWriter has been created with this object, changes to this object will not affect the IndexWriter instance. For that, use LiveIndexWriterConfig that is returned from Config.

LUCENENET NOTE: Unlike Lucene, we use property setters instead of setter methods. In C#, this allows you to initialize the IndexWriterConfig using the language features of C#, for example:

    IndexWriterConfig conf = new IndexWriterConfig(analyzer)
    {
        Codec = Lucene46Codec(),
        OpenMode = OpenMode.CREATE
    };

However, if you prefer to match the syntax of Lucene using chained setter methods, there are extension methods in the Lucene.Net.Support namespace. Example usage:

    using Lucene.Net.Support;

    ..

    IndexWriterConfig conf = new IndexWriterConfig(analyzer)
        .SetCodec(new Lucene46Codec())
        .SetOpenMode(OpenMode.CREATE);

@since 3.1

Inheritance

System.Object

LiveIndexWriterConfig

IndexWriterConfig

Inherited Members

LiveIndexWriterConfig.Analyzer

LiveIndexWriterConfig.TermIndexInterval

LiveIndexWriterConfig.MaxBufferedDeleteTerms

LiveIndexWriterConfig.RAMBufferSizeMB

LiveIndexWriterConfig.MaxBufferedDocs

LiveIndexWriterConfig.MergedSegmentWarmer

LiveIndexWriterConfig.ReaderTermsIndexDivisor

LiveIndexWriterConfig.InfoStream

LiveIndexWriterConfig.UseCompoundFile

LiveIndexWriterConfig.CheckIntegrityAtMerge

Assembly: DistributedLucene.Net.dll

Syntax

public sealed class IndexWriterConfig : LiveIndexWriterConfig

Constructors

Name	Description
IndexWriterConfig(LuceneVersion, Analyzer)	Creates a new config that with defaults that match the specified LuceneVersion as well as the default Analyzer. If `matchVersion` is >= LUCENE_32, TieredMergePolicy is used for merging; else LogByteSizeMergePolicy. Note that TieredMergePolicy is free to select non-contiguous merges, which means docIDs may not remain monotonic over time. If this is a problem you should switch to LogByteSizeMergePolicy or LogDocMergePolicy.

Fields

Name	Description
DEFAULT_CHECK_INTEGRITY_AT_MERGE	Default value for calling CheckIntegrity() before merging segments (set to `false`). You can set this to `true` for additional safety.
DEFAULT_MAX_BUFFERED_DELETE_TERMS	Disabled by default (because IndexWriter flushes by RAM usage by default).
DEFAULT_MAX_BUFFERED_DOCS	Disabled by default (because IndexWriter flushes by RAM usage by default).
DEFAULT_MAX_THREAD_STATES	The maximum number of simultaneous threads that may be indexing documents at once in IndexWriter; if more than this many threads arrive they will wait for others to finish. Default value is 8.
DEFAULT_RAM_BUFFER_SIZE_MB	Default value is 16 MB (which means flush when buffered docs consume approximately 16 MB RAM).
DEFAULT_RAM_PER_THREAD_HARD_LIMIT_MB	Default value is 1945. Change using RAMPerThreadHardLimitMB setter.
DEFAULT_READER_POOLING	Default setting for UseReaderPooling.
DEFAULT_READER_TERMS_INDEX_DIVISOR	Default value is 1. Change using ReaderTermsIndexDivisor setter.
DEFAULT_TERM_INDEX_INTERVAL	Default value is 32. Change using TermIndexInterval setter.
DEFAULT_USE_COMPOUND_FILE_SYSTEM	Default value for compound file system for newly written segments (set to `true`). For batch indexing with very large ram buffers use `false`
DISABLE_AUTO_FLUSH	Denotes a flush trigger is disabled.
WRITE_LOCK_TIMEOUT	Default value for the write lock timeout (1,000 ms).

Properties

Name	Description
Codec	Gets or sets the Codec. Only takes effect when IndexWriter is first created.
DefaultWriteLockTimeout	Gets or sets the default (for any instance) maximum time to wait for a write lock (in milliseconds).
IndexCommit	Expert: allows to open a certain commit point. The default is `null` which opens the latest commit point. Only takes effect when IndexWriter is first created.
IndexDeletionPolicy	Expert: allows an optional IndexDeletionPolicy implementation to be specified. You can use this to control when prior commits are deleted from the index. The default policy is KeepOnlyLastCommitDeletionPolicy which removes all prior commits as soon as a new commit is done (this matches behavior before 2.2). Creating your own policy can allow you to explicitly keep previous "point in time" commits alive in the index for some time, to allow readers to refresh to the new commit without having the old commit deleted out from under them. This is necessary on filesystems like NFS that do not support "delete on last close" semantics, which Lucene's "point in time" search normally relies on. NOTE: the deletion policy cannot be `null`. Only takes effect when IndexWriter is first created.
MaxThreadStates	Gets or sets the max number of simultaneous threads that may be indexing documents at once in IndexWriter. Values < 1 are invalid and if passed `maxThreadStates` will be set to DEFAULT_MAX_THREAD_STATES. Only takes effect when IndexWriter is first created.
MergePolicy	Expert: MergePolicy is invoked whenever there are changes to the segments in the index. Its role is to select which merges to do, if any, and return a MergePolicy.MergeSpecification describing the merges. It also selects merges to do for ForceMerge(Int32). Only takes effect when IndexWriter is first created.
MergeScheduler	Expert: Gets or sets the merge scheduler used by this writer. The default is ConcurrentMergeScheduler. NOTE: the merge scheduler cannot be `null`. Only takes effect when IndexWriter is first created.
OpenMode	Specifies OpenMode of the index. Only takes effect when IndexWriter is first created.
RAMPerThreadHardLimitMB	Expert: Gets or sets the maximum memory consumption per thread triggering a forced flush if exceeded. A Lucene.Net.Index.DocumentsWriterPerThread is forcefully flushed once it exceeds this limit even if the RAMBufferSizeMB has not been exceeded. This is a safety limit to prevent a Lucene.Net.Index.DocumentsWriterPerThread from address space exhaustion due to its internal 32 bit signed integer based memory addressing. The given value must be less that 2GB (2048MB).
Similarity	Expert: set the Similarity implementation used by this IndexWriter. NOTE: the similarity cannot be `null`. Only takes effect when IndexWriter is first created.
UseReaderPooling	By default, IndexWriter does not pool the SegmentReaders it must open for deletions and merging, unless a near-real-time reader has been obtained by calling Open(IndexWriter, Boolean). this setting lets you enable pooling without getting a near-real-time reader. NOTE: if you set this to `false`, IndexWriter will still pool readers once Open(IndexWriter, Boolean) is called. Only takes effect when IndexWriter is first created.
WriteLockTimeout	Gets or sets the maximum time to wait for a write lock (in milliseconds) for this instance. You can change the default value for all instances by calling the DefaultWriteLockTimeout setter. Only takes effect when IndexWriter is first created.

Methods

Name	Description
Clone()
SetInfoStream(InfoStream)	Information about merges, deletes and a message when maxFieldLength is reached will be printed to this. Must not be `null`, but NO_OUTPUT may be used to supress output.
SetInfoStream(TextWriter)	Convenience method that uses TextWriterInfoStream to write to the passed in . Must not be `null`.
ToString()