IndexWriterConfig (Lucene 4.0.0 API)

java.lang.Object
- org.apache.lucene.index.LiveIndexWriterConfig
- - org.apache.lucene.index.IndexWriterConfig

All Implemented Interfaces:

Cloneable
```
public final class IndexWriterConfig
extends LiveIndexWriterConfig
implements Cloneable
```
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 IndexWriter.getConfig().
All setter methods return IndexWriterConfig to allow chaining settings conveniently, for example:
```
 IndexWriterConfig conf = new IndexWriterConfig(analyzer);
 conf.setter1().setter2();
 
```
Since:

3.1

See Also:
IndexWriter.getConfig()

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class IndexWriterConfig.OpenMode
Specifies the open mode for IndexWriter.

Nested Classes
Modifier and Type	Class and Description
`static class`	`IndexWriterConfig.OpenMode` Specifies the open mode for `IndexWriter`.

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`DEFAULT_MAX_BUFFERED_DELETE_TERMS` Disabled by default (because IndexWriter flushes by RAM usage by default).
`static int`	`DEFAULT_MAX_BUFFERED_DOCS` Disabled by default (because IndexWriter flushes by RAM usage by default).
`static int`	`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.
`static double`	`DEFAULT_RAM_BUFFER_SIZE_MB` Default value is 16 MB (which means flush when buffered docs consume approximately 16 MB RAM).
`static int`	`DEFAULT_RAM_PER_THREAD_HARD_LIMIT_MB` Default value is 1945.
`static boolean`	`DEFAULT_READER_POOLING` Default setting for `setReaderPooling(boolean)`.
`static int`	`DEFAULT_READER_TERMS_INDEX_DIVISOR` Default value is 1.
`static int`	`DEFAULT_TERM_INDEX_INTERVAL` Default value is 32.
`static int`	`DISABLE_AUTO_FLUSH` Denotes a flush trigger is disabled.
`static long`	`WRITE_LOCK_TIMEOUT` Default value for the write lock timeout (1,000 ms).

Fields inherited from class org.apache.lucene.index.LiveIndexWriterConfig
codec, commit, delPolicy, flushPolicy, indexerThreadPool, indexingChain, infoStream, matchVersion, mergePolicy, mergeScheduler, openMode, perThreadHardLimitMB, readerPooling, similarity, writeLockTimeout

Constructor Summary

Constructors
Constructor and Description
`IndexWriterConfig(Version matchVersion, Analyzer analyzer)` Creates a new config that with defaults that match the specified `Version` as well as the default `Analyzer`.

Method Summary

Methods
Modifier and Type	Method and Description
`IndexWriterConfig`	`clone()`
`Analyzer`	`getAnalyzer()` Returns the default analyzer to use for indexing documents.
`Codec`	`getCodec()` Returns the current `Codec`.
`static long`	`getDefaultWriteLockTimeout()` Returns the default write lock timeout for newly instantiated IndexWriterConfigs.
`IndexCommit`	`getIndexCommit()` Returns the `IndexCommit` as specified in `setIndexCommit(IndexCommit)` or the default, `null` which specifies to open the latest index commit point.
`IndexDeletionPolicy`	`getIndexDeletionPolicy()` Returns the `IndexDeletionPolicy` specified in `setIndexDeletionPolicy(IndexDeletionPolicy)` or the default `KeepOnlyLastCommitDeletionPolicy`/
`InfoStream`	`getInfoStream()` Returns `InfoStream` used for debugging.
`int`	`getMaxBufferedDeleteTerms()` Returns the number of buffered deleted terms that will trigger a flush of all buffered deletes if enabled.
`int`	`getMaxBufferedDocs()` Returns the number of buffered added documents that will trigger a flush if enabled.
`int`	`getMaxThreadStates()` Returns the max number of simultaneous threads that may be indexing documents at once in IndexWriter.
`IndexWriter.IndexReaderWarmer`	`getMergedSegmentWarmer()` Returns the current merged segment warmer.
`MergePolicy`	`getMergePolicy()` Returns the current MergePolicy in use by this writer.
`MergeScheduler`	`getMergeScheduler()` Returns the `MergeScheduler` that was set by `setMergeScheduler(MergeScheduler)`.
`IndexWriterConfig.OpenMode`	`getOpenMode()` Returns the `IndexWriterConfig.OpenMode` set by `setOpenMode(OpenMode)`.
`double`	`getRAMBufferSizeMB()` Returns the value set by `LiveIndexWriterConfig.setRAMBufferSizeMB(double)` if enabled.
`int`	`getRAMPerThreadHardLimitMB()` Returns the max amount of memory each `DocumentsWriterPerThread` can consume until forcefully flushed.
`boolean`	`getReaderPooling()` Returns `true` if `IndexWriter` should pool readers even if `DirectoryReader.open(IndexWriter, boolean)` has not been called.
`int`	`getReaderTermsIndexDivisor()` Returns the `termInfosIndexDivisor`.
`Similarity`	`getSimilarity()` Expert: returns the `Similarity` implementation used by this `IndexWriter`.
`int`	`getTermIndexInterval()` Returns the interval between indexed terms.
`long`	`getWriteLockTimeout()` Returns allowed timeout when acquiring the write lock.
`IndexWriterConfig`	`setCodec(Codec codec)` Set the `Codec`.
`static void`	`setDefaultWriteLockTimeout(long writeLockTimeout)` Sets the default (for any instance) maximum time to wait for a write lock (in milliseconds).
`IndexWriterConfig`	`setIndexCommit(IndexCommit commit)` Expert: allows to open a certain commit point.
`IndexWriterConfig`	`setIndexDeletionPolicy(IndexDeletionPolicy delPolicy)` Expert: allows an optional `IndexDeletionPolicy` implementation to be specified.
`IndexWriterConfig`	`setInfoStream(InfoStream infoStream)` If non-null, information about merges, deletes and a message when maxFieldLength is reached will be printed to this.
`IndexWriterConfig`	`setInfoStream(PrintStream printStream)` Convenience method that uses `PrintStreamInfoStream`
`IndexWriterConfig`	`setMaxBufferedDeleteTerms(int maxBufferedDeleteTerms)` Determines the minimal number of delete terms required before the buffered in-memory delete terms and queries are applied and flushed.
`IndexWriterConfig`	`setMaxBufferedDocs(int maxBufferedDocs)` Determines the minimal number of documents required before the buffered in-memory documents are flushed as a new Segment.
`IndexWriterConfig`	`setMaxThreadStates(int maxThreadStates)` Sets the max number of simultaneous threads that may be indexing documents at once in IndexWriter.
`IndexWriterConfig`	`setMergedSegmentWarmer(IndexWriter.IndexReaderWarmer mergeSegmentWarmer)` Set the merged segment warmer.
`IndexWriterConfig`	`setMergePolicy(MergePolicy mergePolicy)` Expert: `MergePolicy` is invoked whenever there are changes to the segments in the index.
`IndexWriterConfig`	`setMergeScheduler(MergeScheduler mergeScheduler)` Expert: sets the merge scheduler used by this writer.
`IndexWriterConfig`	`setOpenMode(IndexWriterConfig.OpenMode openMode)` Specifies `IndexWriterConfig.OpenMode` of the index.
`IndexWriterConfig`	`setRAMBufferSizeMB(double ramBufferSizeMB)` Determines the amount of RAM that may be used for buffering added documents and deletions before they are flushed to the Directory.
`IndexWriterConfig`	`setRAMPerThreadHardLimitMB(int perThreadHardLimitMB)` Expert: Sets the maximum memory consumption per thread triggering a forced flush if exceeded.
`IndexWriterConfig`	`setReaderPooling(boolean readerPooling)` 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 `DirectoryReader.open(IndexWriter, boolean)`.
`IndexWriterConfig`	`setReaderTermsIndexDivisor(int divisor)` Sets the termsIndexDivisor passed to any readers that IndexWriter opens, for example when applying deletes or creating a near-real-time reader in `DirectoryReader.open(IndexWriter, boolean)`.
`IndexWriterConfig`	`setSimilarity(Similarity similarity)` Expert: set the `Similarity` implementation used by this IndexWriter.
`IndexWriterConfig`	`setTermIndexInterval(int interval)` Expert: set the interval between indexed terms.
`IndexWriterConfig`	`setWriteLockTimeout(long writeLockTimeout)` Sets the maximum time to wait for a write lock (in milliseconds) for this instance.

Methods inherited from class org.apache.lucene.index.LiveIndexWriterConfig
toString

Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - DEFAULT_TERM_INDEX_INTERVAL
```
public static final int DEFAULT_TERM_INDEX_INTERVAL
```
    Default value is 32. Change using setTermIndexInterval(int).
    
    See Also:
    Constant Field Values
  - DISABLE_AUTO_FLUSH
```
public static final int DISABLE_AUTO_FLUSH
```
    Denotes a flush trigger is disabled.
    
    See Also:
    Constant Field Values
  - DEFAULT_MAX_BUFFERED_DELETE_TERMS
```
public static final int DEFAULT_MAX_BUFFERED_DELETE_TERMS
```
    Disabled by default (because IndexWriter flushes by RAM usage by default).
    
    See Also:
    Constant Field Values
  - DEFAULT_MAX_BUFFERED_DOCS
```
public static final int DEFAULT_MAX_BUFFERED_DOCS
```
    Disabled by default (because IndexWriter flushes by RAM usage by default).
    
    See Also:
    Constant Field Values
  - DEFAULT_RAM_BUFFER_SIZE_MB
```
public static final double DEFAULT_RAM_BUFFER_SIZE_MB
```
    Default value is 16 MB (which means flush when buffered docs consume approximately 16 MB RAM).
    
    See Also:
    Constant Field Values
  - WRITE_LOCK_TIMEOUT
```
public static long WRITE_LOCK_TIMEOUT
```
    Default value for the write lock timeout (1,000 ms).
    
    See Also:
    setDefaultWriteLockTimeout(long)
  - DEFAULT_READER_POOLING
```
public static final boolean DEFAULT_READER_POOLING
```
    Default setting for setReaderPooling(boolean).
    
    See Also:
    Constant Field Values
  - DEFAULT_READER_TERMS_INDEX_DIVISOR
```
public static final int DEFAULT_READER_TERMS_INDEX_DIVISOR
```
    Default value is 1. Change using setReaderTermsIndexDivisor(int).
    
    See Also:
    Constant Field Values
  - DEFAULT_RAM_PER_THREAD_HARD_LIMIT_MB
```
public static final int DEFAULT_RAM_PER_THREAD_HARD_LIMIT_MB
```
    Default value is 1945. Change using setRAMPerThreadHardLimitMB(int)
    
    See Also:
    Constant Field Values
  - DEFAULT_MAX_THREAD_STATES
```
public static final int 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.
    
    See Also:
    Constant Field Values
- Constructor Detail
  - IndexWriterConfig
```
public IndexWriterConfig(Version matchVersion,
                 Analyzer analyzer)
```
    Creates a new config that with defaults that match the specified Version as well as the default Analyzer. If matchVersion is >= Version.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.
- Method Detail
  - setDefaultWriteLockTimeout
```
public static void setDefaultWriteLockTimeout(long writeLockTimeout)
```
    Sets the default (for any instance) maximum time to wait for a write lock (in milliseconds).
  - getDefaultWriteLockTimeout
```
public static long getDefaultWriteLockTimeout()
```
    Returns the default write lock timeout for newly instantiated IndexWriterConfigs.
    
    See Also:
    setDefaultWriteLockTimeout(long)
  - clone
```
public IndexWriterConfig clone()
```
    Overrides:
    
    clone in class Object
  - setOpenMode
```
public IndexWriterConfig setOpenMode(IndexWriterConfig.OpenMode openMode)
```
    Specifies IndexWriterConfig.OpenMode of the index.
    Only takes effect when IndexWriter is first created.
  - getOpenMode
```
public IndexWriterConfig.OpenMode getOpenMode()
```
    Description copied from class: LiveIndexWriterConfig
    
    Returns the IndexWriterConfig.OpenMode set by setOpenMode(OpenMode).
    
    Overrides:
    
    getOpenMode in class LiveIndexWriterConfig
  - setIndexDeletionPolicy
```
public IndexWriterConfig setIndexDeletionPolicy(IndexDeletionPolicy delPolicy)
```
    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. If null is passed, the deletion policy will be set to the default.
    Only takes effect when IndexWriter is first created.
  - getIndexDeletionPolicy
```
public IndexDeletionPolicy getIndexDeletionPolicy()
```
    Description copied from class: LiveIndexWriterConfig
    
    Returns the IndexDeletionPolicy specified in setIndexDeletionPolicy(IndexDeletionPolicy) or the default KeepOnlyLastCommitDeletionPolicy/
    
    Overrides:
    
    getIndexDeletionPolicy in class LiveIndexWriterConfig
  - setIndexCommit
```
public IndexWriterConfig setIndexCommit(IndexCommit commit)
```
    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.
  - getIndexCommit
```
public IndexCommit getIndexCommit()
```
    Description copied from class: LiveIndexWriterConfig
    
    Returns the IndexCommit as specified in setIndexCommit(IndexCommit) or the default, null which specifies to open the latest index commit point.
    
    Overrides:
    
    getIndexCommit in class LiveIndexWriterConfig
  - setSimilarity
```
public IndexWriterConfig setSimilarity(Similarity similarity)
```
    Expert: set the Similarity implementation used by this IndexWriter.
    NOTE: the similarity cannot be null. If null is passed, the similarity will be set to the default implementation (unspecified).
    Only takes effect when IndexWriter is first created.
  - getSimilarity
```
public Similarity getSimilarity()
```
    Description copied from class: LiveIndexWriterConfig
    
    Expert: returns the Similarity implementation used by this IndexWriter.
    
    Overrides:
    
    getSimilarity in class LiveIndexWriterConfig
  - setMergeScheduler
```
public IndexWriterConfig setMergeScheduler(MergeScheduler mergeScheduler)
```
    Expert: sets the merge scheduler used by this writer. The default is ConcurrentMergeScheduler.
    NOTE: the merge scheduler cannot be null. If null is passed, the merge scheduler will be set to the default.
    Only takes effect when IndexWriter is first created.
  - getMergeScheduler
```
public MergeScheduler getMergeScheduler()
```
    Description copied from class: LiveIndexWriterConfig
    
    Returns the MergeScheduler that was set by setMergeScheduler(MergeScheduler).
    
    Overrides:
    
    getMergeScheduler in class LiveIndexWriterConfig
  - setWriteLockTimeout
```
public IndexWriterConfig setWriteLockTimeout(long writeLockTimeout)
```
    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 setDefaultWriteLockTimeout(long).
    Only takes effect when IndexWriter is first created.
  - getWriteLockTimeout
```
public long getWriteLockTimeout()
```
    Description copied from class: LiveIndexWriterConfig
    
    Returns allowed timeout when acquiring the write lock.
    
    Overrides:
    
    getWriteLockTimeout in class LiveIndexWriterConfig
    
    See Also:
    setWriteLockTimeout(long)
  - setMergePolicy
```
public IndexWriterConfig setMergePolicy(MergePolicy 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. (The default is LogByteSizeMergePolicy.
    Only takes effect when IndexWriter is first created.
  - setCodec
```
public IndexWriterConfig setCodec(Codec codec)
```
    Set the Codec.
    Only takes effect when IndexWriter is first created.
  - getCodec
```
public Codec getCodec()
```
    Description copied from class: LiveIndexWriterConfig
    
    Returns the current Codec.
    
    Overrides:
    
    getCodec in class LiveIndexWriterConfig
  - getMergePolicy
```
public MergePolicy getMergePolicy()
```
    Description copied from class: LiveIndexWriterConfig
    
    Returns the current MergePolicy in use by this writer.
    
    Overrides:
    
    getMergePolicy in class LiveIndexWriterConfig
    
    See Also:
    setMergePolicy(MergePolicy)
  - setMaxThreadStates
```
public IndexWriterConfig setMaxThreadStates(int maxThreadStates)
```
    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.
  - getMaxThreadStates
```
public int getMaxThreadStates()
```
    Description copied from class: LiveIndexWriterConfig
    
    Returns the max number of simultaneous threads that may be indexing documents at once in IndexWriter.
    
    Overrides:
    
    getMaxThreadStates in class LiveIndexWriterConfig
  - setReaderPooling
```
public IndexWriterConfig setReaderPooling(boolean readerPooling)
```
    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 DirectoryReader.open(IndexWriter, boolean). This method lets you enable pooling without getting a near-real-time reader. NOTE: if you set this to false, IndexWriter will still pool readers once DirectoryReader.open(IndexWriter, boolean) is called.
    Only takes effect when IndexWriter is first created.
  - getReaderPooling
```
public boolean getReaderPooling()
```
    Description copied from class: LiveIndexWriterConfig
    
    Returns true if IndexWriter should pool readers even if DirectoryReader.open(IndexWriter, boolean) has not been called.
    
    Overrides:
    
    getReaderPooling in class LiveIndexWriterConfig
  - setRAMPerThreadHardLimitMB
```
public IndexWriterConfig setRAMPerThreadHardLimitMB(int perThreadHardLimitMB)
```
    Expert: Sets the maximum memory consumption per thread triggering a forced flush if exceeded. A DocumentsWriterPerThread is forcefully flushed once it exceeds this limit even if the getRAMBufferSizeMB() has not been exceeded. This is a safety limit to prevent a 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)
    
    See Also:
    DEFAULT_RAM_PER_THREAD_HARD_LIMIT_MB
  - getRAMPerThreadHardLimitMB
```
public int getRAMPerThreadHardLimitMB()
```
    Description copied from class: LiveIndexWriterConfig
    
    Returns the max amount of memory each DocumentsWriterPerThread can consume until forcefully flushed.
    
    Overrides:
    
    getRAMPerThreadHardLimitMB in class LiveIndexWriterConfig
    
    See Also:
    setRAMPerThreadHardLimitMB(int)
  - getInfoStream
```
public InfoStream getInfoStream()
```
    Description copied from class: LiveIndexWriterConfig
    
    Returns InfoStream used for debugging.
    
    Overrides:
    
    getInfoStream in class LiveIndexWriterConfig
    
    See Also:
    setInfoStream(InfoStream)
  - getAnalyzer
```
public Analyzer getAnalyzer()
```
    Description copied from class: LiveIndexWriterConfig
    
    Returns the default analyzer to use for indexing documents.
    
    Overrides:
    
    getAnalyzer in class LiveIndexWriterConfig
  - getMaxBufferedDeleteTerms
```
public int getMaxBufferedDeleteTerms()
```
    Description copied from class: LiveIndexWriterConfig
    
    Returns the number of buffered deleted terms that will trigger a flush of all buffered deletes if enabled.
    
    Overrides:
    
    getMaxBufferedDeleteTerms in class LiveIndexWriterConfig
    
    See Also:
    LiveIndexWriterConfig.setMaxBufferedDeleteTerms(int)
  - getMaxBufferedDocs
```
public int getMaxBufferedDocs()
```
    Description copied from class: LiveIndexWriterConfig
    
    Returns the number of buffered added documents that will trigger a flush if enabled.
    
    Overrides:
    
    getMaxBufferedDocs in class LiveIndexWriterConfig
    
    See Also:
    LiveIndexWriterConfig.setMaxBufferedDocs(int)
  - getMergedSegmentWarmer
```
public IndexWriter.IndexReaderWarmer getMergedSegmentWarmer()
```
    Description copied from class: LiveIndexWriterConfig
    
    Returns the current merged segment warmer. See IndexWriter.IndexReaderWarmer.
    
    Overrides:
    
    getMergedSegmentWarmer in class LiveIndexWriterConfig
  - getRAMBufferSizeMB
```
public double getRAMBufferSizeMB()
```
    Description copied from class: LiveIndexWriterConfig
    
    Returns the value set by LiveIndexWriterConfig.setRAMBufferSizeMB(double) if enabled.
    
    Overrides:
    
    getRAMBufferSizeMB in class LiveIndexWriterConfig
  - getReaderTermsIndexDivisor
```
public int getReaderTermsIndexDivisor()
```
    Description copied from class: LiveIndexWriterConfig
    
    Returns the termInfosIndexDivisor.
    
    Overrides:
    
    getReaderTermsIndexDivisor in class LiveIndexWriterConfig
    
    See Also:
    LiveIndexWriterConfig.setReaderTermsIndexDivisor(int)
  - getTermIndexInterval
```
public int getTermIndexInterval()
```
    Description copied from class: LiveIndexWriterConfig
    
    Returns the interval between indexed terms.
    
    Overrides:
    
    getTermIndexInterval in class LiveIndexWriterConfig
    
    See Also:
    LiveIndexWriterConfig.setTermIndexInterval(int)
  - setInfoStream
```
public IndexWriterConfig setInfoStream(InfoStream infoStream)
```
    If non-null, information about merges, deletes and a message when maxFieldLength is reached will be printed to this.
  - setInfoStream
```
public IndexWriterConfig setInfoStream(PrintStream printStream)
```
    Convenience method that uses PrintStreamInfoStream
  - setMaxBufferedDeleteTerms
```
public IndexWriterConfig setMaxBufferedDeleteTerms(int maxBufferedDeleteTerms)
```
    Description copied from class: LiveIndexWriterConfig
    
    Determines the minimal number of delete terms required before the buffered in-memory delete terms and queries are applied and flushed.
    Disabled by default (writer flushes by RAM usage).
    NOTE: This setting won't trigger a segment flush.
    Takes effect immediately, but only the next time a document is added, updated or deleted.
    
    Overrides:
    
    setMaxBufferedDeleteTerms in class LiveIndexWriterConfig
    
    See Also:
    LiveIndexWriterConfig.setRAMBufferSizeMB(double)
  - setMaxBufferedDocs
```
public IndexWriterConfig setMaxBufferedDocs(int maxBufferedDocs)
```
    Description copied from class: LiveIndexWriterConfig
    
    Determines the minimal number of documents required before the buffered in-memory documents are flushed as a new Segment. Large values generally give faster indexing.
    When this is set, the writer will flush every maxBufferedDocs added documents. Pass in DISABLE_AUTO_FLUSH to prevent triggering a flush due to number of buffered documents. Note that if flushing by RAM usage is also enabled, then the flush will be triggered by whichever comes first.
    Disabled by default (writer flushes by RAM usage).
    Takes effect immediately, but only the next time a document is added, updated or deleted.
    
    Overrides:
    
    setMaxBufferedDocs in class LiveIndexWriterConfig
    
    See Also:
    LiveIndexWriterConfig.setRAMBufferSizeMB(double)
  - setMergedSegmentWarmer
```
public IndexWriterConfig setMergedSegmentWarmer(IndexWriter.IndexReaderWarmer mergeSegmentWarmer)
```
    Description copied from class: LiveIndexWriterConfig
    
    Set the merged segment warmer. See IndexWriter.IndexReaderWarmer.
    Takes effect on the next merge.
    
    Overrides:
    
    setMergedSegmentWarmer in class LiveIndexWriterConfig
  - setRAMBufferSizeMB
```
public IndexWriterConfig setRAMBufferSizeMB(double ramBufferSizeMB)
```
    Description copied from class: LiveIndexWriterConfig
    
    Determines the amount of RAM that may be used for buffering added documents and deletions before they are flushed to the Directory. Generally for faster indexing performance it's best to flush by RAM usage instead of document count and use as large a RAM buffer as you can.
    When this is set, the writer will flush whenever buffered documents and deletions use this much RAM. Pass in DISABLE_AUTO_FLUSH to prevent triggering a flush due to RAM usage. Note that if flushing by document count is also enabled, then the flush will be triggered by whichever comes first.
    The maximum RAM limit is inherently determined by the JVMs available memory. Yet, an IndexWriter session can consume a significantly larger amount of memory than the given RAM limit since this limit is just an indicator when to flush memory resident documents to the Directory. Flushes are likely happen concurrently while other threads adding documents to the writer. For application stability the available memory in the JVM should be significantly larger than the RAM buffer used for indexing.
    NOTE: the account of RAM usage for pending deletions is only approximate. Specifically, if you delete by Query, Lucene currently has no way to measure the RAM usage of individual Queries so the accounting will under-estimate and you should compensate by either calling commit() periodically yourself, or by using LiveIndexWriterConfig.setMaxBufferedDeleteTerms(int) to flush and apply buffered deletes by count instead of RAM usage (for each buffered delete Query a constant number of bytes is used to estimate RAM usage). Note that enabling LiveIndexWriterConfig.setMaxBufferedDeleteTerms(int) will not trigger any segment flushes.
    NOTE: It's not guaranteed that all memory resident documents are flushed once this limit is exceeded. Depending on the configured FlushPolicy only a subset of the buffered documents are flushed and therefore only parts of the RAM buffer is released.
    The default value is DEFAULT_RAM_BUFFER_SIZE_MB.
    Takes effect immediately, but only the next time a document is added, updated or deleted.
    
    Overrides:
    
    setRAMBufferSizeMB in class LiveIndexWriterConfig
    
    See Also:
    setRAMPerThreadHardLimitMB(int)
  - setReaderTermsIndexDivisor
```
public IndexWriterConfig setReaderTermsIndexDivisor(int divisor)
```
    Description copied from class: LiveIndexWriterConfig
    
    Sets the termsIndexDivisor passed to any readers that IndexWriter opens, for example when applying deletes or creating a near-real-time reader in DirectoryReader.open(IndexWriter, boolean). If you pass -1, the terms index won't be loaded by the readers. This is only useful in advanced situations when you will only .next() through all terms; attempts to seek will hit an exception.
    Takes effect immediately, but only applies to readers opened after this call
    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.
    
    Overrides:
    
    setReaderTermsIndexDivisor in class LiveIndexWriterConfig
  - setTermIndexInterval
```
public IndexWriterConfig setTermIndexInterval(int interval)
```
    Description copied from class: LiveIndexWriterConfig
    Expert: set the interval between indexed terms. Large values cause less memory to be used by IndexReader, but slow random-access to terms. Small values cause more memory to be used by an IndexReader, and speed random-access to terms.
    This parameter determines the amount of computation required per query term, regardless of the number of documents that contain that term. In particular, it is the maximum number of other terms that must be scanned before a term is located and its frequency and position information may be processed. In a large index with user-entered query terms, query processing time is likely to be dominated not by term lookup but rather by the processing of frequency and positional data. In a small index or when many uncommon query terms are generated (e.g., by wildcard queries) term lookup may become a dominant cost.
    In particular, numUniqueTerms/interval terms are read into memory by an IndexReader, and, on average, interval/2 terms must be scanned for each random term access.
    Takes effect immediately, but only applies to newly flushed/merged segments.
    NOTE: This parameter does not apply to all PostingsFormat implementations, including the default one in this release. It only makes sense for term indexes that are implemented as a fixed gap between terms. For example, Lucene40PostingsFormat implements the term index instead based upon how terms share prefixes. To configure its parameters (the minimum and maximum size for a block), you would instead use Lucene40PostingsFormat.Lucene40PostingsFormat(int, int). which can also be configured on a per-field basis:
```
 //customize Lucene40PostingsFormat, passing minBlockSize=50, maxBlockSize=100
 final PostingsFormat tweakedPostings = new Lucene40PostingsFormat(50, 100);
 iwc.setCodec(new Lucene40Codec() {
   @Override
   public PostingsFormat getPostingsFormatForField(String field) {
     if (field.equals("fieldWithTonsOfTerms"))
       return tweakedPostings;
     else
       return super.getPostingsFormatForField(field);
   }
 });
 
```
    Note that other implementations may have their own parameters, or no parameters at all.
    Overrides:
    
    setTermIndexInterval in class LiveIndexWriterConfig
    
    See Also:
    DEFAULT_TERM_INDEX_INTERVAL

Class IndexWriterConfig

Nested Class Summary

Field Summary

Fields inherited from class org.apache.lucene.index.LiveIndexWriterConfig

Constructor Summary

Method Summary

Methods inherited from class org.apache.lucene.index.LiveIndexWriterConfig

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_TERM_INDEX_INTERVAL

DISABLE_AUTO_FLUSH

DEFAULT_MAX_BUFFERED_DELETE_TERMS

DEFAULT_MAX_BUFFERED_DOCS

DEFAULT_RAM_BUFFER_SIZE_MB

WRITE_LOCK_TIMEOUT

DEFAULT_READER_POOLING

DEFAULT_READER_TERMS_INDEX_DIVISOR

DEFAULT_RAM_PER_THREAD_HARD_LIMIT_MB

DEFAULT_MAX_THREAD_STATES

Constructor Detail

IndexWriterConfig

Method Detail

setDefaultWriteLockTimeout

getDefaultWriteLockTimeout

clone

setOpenMode

getOpenMode

setIndexDeletionPolicy

getIndexDeletionPolicy

setIndexCommit

getIndexCommit

setSimilarity

getSimilarity

setMergeScheduler

getMergeScheduler

setWriteLockTimeout

getWriteLockTimeout

setMergePolicy

setCodec

getCodec

getMergePolicy

setMaxThreadStates

getMaxThreadStates

setReaderPooling

getReaderPooling

setRAMPerThreadHardLimitMB

getRAMPerThreadHardLimitMB

getInfoStream

getAnalyzer

getMaxBufferedDeleteTerms

getMaxBufferedDocs

getMergedSegmentWarmer

getRAMBufferSizeMB

getReaderTermsIndexDivisor

getTermIndexInterval

setInfoStream

setInfoStream

setMaxBufferedDeleteTerms

setMaxBufferedDocs

setMergedSegmentWarmer

setRAMBufferSizeMB

setReaderTermsIndexDivisor

setTermIndexInterval