IndexWriterConfig (Lucene 8.5.0 API)

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

```
public final class IndexWriterConfig
extends LiveIndexWriterConfig
```
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 boolean`	`DEFAULT_COMMIT_ON_CLOSE` Default value for whether calls to `IndexWriter.close()` include a commit.
`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 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 (true) for `setReaderPooling(boolean)`.
`static boolean`	`DEFAULT_USE_COMPOUND_FILE_SYSTEM` Default value for compound file system for newly written segments (set to `true`).
`static int`	`DISABLE_AUTO_FLUSH` Denotes a flush trigger is disabled.

Fields inherited from class org.apache.lucene.index.LiveIndexWriterConfig
checkPendingFlushOnUpdate, codec, commit, commitOnClose, createdVersionMajor, delPolicy, flushPolicy, indexerThreadPool, indexingChain, indexSort, indexSortFields, infoStream, mergePolicy, mergeScheduler, openMode, perThreadHardLimitMB, readerAttributes, readerPooling, similarity, softDeletesField, useCompoundFile

Constructor Summary

Constructors
Constructor and Description
`IndexWriterConfig()` Creates a new config, using `StandardAnalyzer` as the analyzer.
`IndexWriterConfig(Analyzer analyzer)` Creates a new config that with the provided `Analyzer`.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`Analyzer`	`getAnalyzer()` Returns the default analyzer to use for indexing documents.
`Codec`	`getCodec()` Returns the current `Codec`.
`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`	`getMaxBufferedDocs()` Returns the number of buffered added documents that will trigger a flush if enabled.
`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)` has not been called.
`Similarity`	`getSimilarity()` Expert: returns the `Similarity` implementation used by this `IndexWriter`.
`IndexWriterConfig`	`setCheckPendingFlushUpdate(boolean checkPendingFlushOnUpdate)` Expert: sets if indexing threads check for pending flushes on update in order to help our flushing indexing buffers to disk.
`IndexWriterConfig`	`setCodec(Codec codec)` Set the `Codec`.
`IndexWriterConfig`	`setCommitOnClose(boolean commitOnClose)` Sets if calls `IndexWriter.close()` should first commit before closing.
`IndexWriterConfig`	`setIndexCommit(IndexCommit commit)` Expert: allows to open a certain commit point.
`IndexWriterConfig`	`setIndexCreatedVersionMajor(int indexCreatedVersionMajor)` Expert: set the compatibility version to use for this index.
`IndexWriterConfig`	`setIndexDeletionPolicy(IndexDeletionPolicy delPolicy)` Expert: allows an optional `IndexDeletionPolicy` implementation to be specified.
`IndexWriterConfig`	`setIndexSort(Sort sort)` Set the `Sort` order to use for all (flushed and merged) segments.
`IndexWriterConfig`	`setInfoStream(InfoStream infoStream)` 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`	`setMaxBufferedDocs(int maxBufferedDocs)` Determines the minimal number of documents required before the buffered in-memory documents are flushed as a new Segment.
`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`	`setReaderAttributes(Map<String,String> readerAttributes)` Sets the reader attributes used for all readers pulled from the IndexWriter.
`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)`.
`IndexWriterConfig`	`setSimilarity(Similarity similarity)` Expert: set the `Similarity` implementation used by this IndexWriter.
`IndexWriterConfig`	`setSoftDeletesField(String softDeletesField)` Sets the soft deletes field.
`IndexWriterConfig`	`setUseCompoundFile(boolean useCompoundFile)` Sets if the `IndexWriter` should pack newly written segments in a compound file.
`String`	`toString()`

Methods inherited from class org.apache.lucene.index.LiveIndexWriterConfig
getCommitOnClose, getIndexCreatedVersionMajor, getIndexSort, getIndexSortFields, getReaderAttributes, getSoftDeletesField, getUseCompoundFile, isCheckPendingFlushOnUpdate

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

- Field Detail
  - 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
  - DEFAULT_READER_POOLING
```
public static final boolean DEFAULT_READER_POOLING
```
    Default setting (true) for setReaderPooling(boolean).
    
    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_USE_COMPOUND_FILE_SYSTEM
```
public static final boolean 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
    
    See Also:
    
    Constant Field Values
  - DEFAULT_COMMIT_ON_CLOSE
```
public static final boolean DEFAULT_COMMIT_ON_CLOSE
```
    Default value for whether calls to IndexWriter.close() include a commit.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - IndexWriterConfig
```
public IndexWriterConfig()
```
    Creates a new config, using StandardAnalyzer as the analyzer. By default, TieredMergePolicy is used for merging; 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.
  - IndexWriterConfig
```
public IndexWriterConfig(Analyzer analyzer)
```
    Creates a new config that with the provided Analyzer. By default, TieredMergePolicy is used for merging; 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
  - 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
  - setIndexCreatedVersionMajor
```
public IndexWriterConfig setIndexCreatedVersionMajor(int indexCreatedVersionMajor)
```
    Expert: set the compatibility version to use for this index. In case the index is created, it will use the given major version for compatibility. It is sometimes useful to set the previous major version for compatibility due to the fact that IndexWriter.addIndexes(org.apache.lucene.store.Directory...) only accepts indices that have been written with the same major version as the current index. If the index already exists, then this value is ignored. Default value is the major of the latest version.
    NOTE: Changing the creation version reduces backward compatibility guarantees. For instance an index created with Lucene 8 with a compatibility version of 7 can't be read with Lucene 9 due to the fact that Lucene only supports reading indices created with the current or previous major release.
    
    Parameters:
    
    indexCreatedVersionMajor - the major version to use for compatibility
  - 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 must not be null.
    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. This can also be used to open IndexWriter from a near-real-time reader, if you pass the reader's DirectoryReader.getIndexCommit().
    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 must not be null.
    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 must not be null.
    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
  - 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)
  - 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). 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) 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) 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
  - 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
  - setInfoStream
```
public IndexWriterConfig setInfoStream(InfoStream infoStream)
```
    Information about merges, deletes and a message when maxFieldLength is reached will be printed to this. Must not be null, but InfoStream.NO_OUTPUT may be used to suppress output.
  - setInfoStream
```
public IndexWriterConfig setInfoStream(PrintStream printStream)
```
    Convenience method that uses PrintStreamInfoStream. Must not be null.
  - setMergePolicy
```
public IndexWriterConfig setMergePolicy(MergePolicy mergePolicy)
```
    Description copied from class: LiveIndexWriterConfig
    
    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.
    Takes effect on subsequent merge selections. Any merges in flight or any merges already registered by the previous MergePolicy are not affected.
    
    Overrides:
    
    setMergePolicy in class LiveIndexWriterConfig
  - 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() or refresh() periodically yourself.
    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)
  - setUseCompoundFile
```
public IndexWriterConfig setUseCompoundFile(boolean useCompoundFile)
```
    Description copied from class: LiveIndexWriterConfig
    
    Sets if the IndexWriter should pack newly written segments in a compound file. Default is true.
    Use false for batch indexing with very large ram buffer settings.
    
    Note: To control compound file usage during segment merges see MergePolicy.setNoCFSRatio(double) and MergePolicy.setMaxCFSSegmentSizeMB(double). This setting only applies to newly created segments.
    
    Overrides:
    
    setUseCompoundFile in class LiveIndexWriterConfig
  - setCommitOnClose
```
public IndexWriterConfig setCommitOnClose(boolean commitOnClose)
```
    Sets if calls IndexWriter.close() should first commit before closing. Use true to match behavior of Lucene 4.x.
  - setIndexSort
```
public IndexWriterConfig setIndexSort(Sort sort)
```
    Set the Sort order to use for all (flushed and merged) segments.
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class LiveIndexWriterConfig
  - setCheckPendingFlushUpdate
```
public IndexWriterConfig setCheckPendingFlushUpdate(boolean checkPendingFlushOnUpdate)
```
    Description copied from class: LiveIndexWriterConfig
    
    Expert: sets if indexing threads check for pending flushes on update in order to help our flushing indexing buffers to disk. As a consequence, threads calling DirectoryReader.openIfChanged(DirectoryReader, IndexWriter) or IndexWriter.flush() will be the only thread writing segments to disk unless flushes are falling behind. If indexing is stalled due to too many pending flushes indexing threads will help our writing pending segment flushes to disk.
    
    Overrides:
    
    setCheckPendingFlushUpdate in class LiveIndexWriterConfig
  - setSoftDeletesField
```
public IndexWriterConfig setSoftDeletesField(String softDeletesField)
```
    Sets the soft deletes field. A soft delete field in lucene is a doc-values field that marks a document as soft-deleted if a document has at least one value in that field. If a document is marked as soft-deleted the document is treated as if it has been hard-deleted through the IndexWriter API (IndexWriter.deleteDocuments(Term...). Merges will reclaim soft-deleted as well as hard-deleted documents and index readers obtained from the IndexWriter will reflect all deleted documents in it's live docs. If soft-deletes are used documents must be indexed via IndexWriter.softUpdateDocument(Term, Iterable, Field...). Deletes are applied via IndexWriter.updateDocValues(Term, Field...). Soft deletes allow to retain documents across merges if the merge policy modifies the live docs of a merge reader. SoftDeletesRetentionMergePolicy for instance allows to specify an arbitrary query to mark all documents that should survive the merge. This can be used to for example keep all document modifications for a certain time interval or the last N operations if some kind of sequence ID is available in the index. Currently there is no API support to un-delete a soft-deleted document. In oder to un-delete the document must be re-indexed using IndexWriter.softUpdateDocument(Term, Iterable, Field...). The default value for this is null which disables soft-deletes. If soft-deletes are enabled documents can still be hard-deleted. Hard-deleted documents will won't considered as soft-deleted even if they have a value in the soft-deletes field.
    
    See Also:
    
    LiveIndexWriterConfig.getSoftDeletesField()
  - setReaderAttributes
```
public IndexWriterConfig setReaderAttributes(Map<String,String> readerAttributes)
```
    Sets the reader attributes used for all readers pulled from the IndexWriter. Reader attributes allow configuration of low-level aspects like ram utilization on a per-reader basis. Note: This method make a shallow copy of the provided map.

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

DISABLE_AUTO_FLUSH

DEFAULT_MAX_BUFFERED_DELETE_TERMS

DEFAULT_MAX_BUFFERED_DOCS

DEFAULT_RAM_BUFFER_SIZE_MB

DEFAULT_READER_POOLING

DEFAULT_RAM_PER_THREAD_HARD_LIMIT_MB

DEFAULT_USE_COMPOUND_FILE_SYSTEM

DEFAULT_COMMIT_ON_CLOSE

Constructor Detail

IndexWriterConfig

IndexWriterConfig

Method Detail

setOpenMode

getOpenMode

setIndexCreatedVersionMajor

setIndexDeletionPolicy

getIndexDeletionPolicy

setIndexCommit

getIndexCommit

setSimilarity

getSimilarity

setMergeScheduler

getMergeScheduler

setCodec

getCodec

getMergePolicy

setReaderPooling

getReaderPooling

setRAMPerThreadHardLimitMB

getRAMPerThreadHardLimitMB

getInfoStream

getAnalyzer

getMaxBufferedDocs

getMergedSegmentWarmer

getRAMBufferSizeMB

setInfoStream

setInfoStream

setMergePolicy

setMaxBufferedDocs

setMergedSegmentWarmer

setRAMBufferSizeMB

setUseCompoundFile

setCommitOnClose

setIndexSort

toString

setCheckPendingFlushUpdate

setSoftDeletesField

setReaderAttributes