Package org.apache.lucene.index

Class IndexWriterConfig

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	Description
static enum	IndexWriterConfig.OpenMode	Specifies the open mode for IndexWriter.

Field Summary

Fields

Modifier and Type	Field	Description
static final boolean	DEFAULT_COMMIT_ON_CLOSE	Default value for whether calls to IndexWriter.close() include a commit.
static final int	DEFAULT_MAX_BUFFERED_DELETE_TERMS	Disabled by default (because IndexWriter flushes by RAM usage by default).
static final int	DEFAULT_MAX_BUFFERED_DOCS	Disabled by default (because IndexWriter flushes by RAM usage by default).
static final long	DEFAULT_MAX_FULL_FLUSH_MERGE_WAIT_MILLIS	Default value for time to wait for merges on commit or getReader (when using a MergePolicy that implements MergePolicy.findFullFlushMerges(org.apache.lucene.index.MergeTrigger, org.apache.lucene.index.SegmentInfos, org.apache.lucene.index.MergePolicy.MergeContext)).
static final double	DEFAULT_RAM_BUFFER_SIZE_MB	Default value is 16 MB (which means flush when buffered docs consume approximately 16 MB RAM).
static final int	DEFAULT_RAM_PER_THREAD_HARD_LIMIT_MB	Default value is 1945.
static final boolean	DEFAULT_READER_POOLING	Default setting (true) for setReaderPooling(boolean).
static final boolean	DEFAULT_USE_COMPOUND_FILE_SYSTEM	Default value for compound file system for newly written segments (set to true).
static final 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, eventListener, flushPolicy, indexSort, indexSortFields, infoStream, leafSorter, maxFullFlushMergeWaitMillis, mergePolicy, mergeScheduler, openMode, perThreadHardLimitMB, readerPooling, similarity, softDeletesField, useCompoundFile

Constructor Summary

Constructors

Constructor	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

Modifier and Type	Method	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	setIndexWriterEventListener(IndexWriterEventListener eventListener)	Set event listener to record key events in IndexWriter
IndexWriterConfig	setInfoStream(PrintStream printStream)	Convenience method that uses PrintStreamInfoStream.
IndexWriterConfig	setInfoStream(InfoStream infoStream)	Information about merges, deletes and a message when maxFieldLength is reached will be printed to this.
IndexWriterConfig	setLeafSorter(Comparator<LeafReader> leafSorter)	Set the comparator for sorting leaf readers.
IndexWriterConfig	setMaxBufferedDocs(int maxBufferedDocs)	Determines the minimal number of documents required before the buffered in-memory documents are flushed as a new Segment.
IndexWriterConfig	setMaxFullFlushMergeWaitMillis(long maxFullFlushMergeWaitMillis)	Expert: sets the amount of time to wait for merges (during IndexWriter.commit() or IndexWriter.getReader(boolean, boolean)) returned by MergePolicy.findFullFlushMerges(...).
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).
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, getIndexWriterEventListener, getLeafSorter, getMaxFullFlushMergeWaitMillis, getSoftDeletesField, getUseCompoundFile, isCheckPendingFlushOnUpdate

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Details

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

DEFAULT_MAX_FULL_FLUSH_MERGE_WAIT_MILLIS

public static final long DEFAULT_MAX_FULL_FLUSH_MERGE_WAIT_MILLIS

Default value for time to wait for merges on commit or getReader (when using a MergePolicy that implements MergePolicy.findFullFlushMerges(org.apache.lucene.index.MergeTrigger, org.apache.lucene.index.SegmentInfos, org.apache.lucene.index.MergePolicy.MergeContext)).

See Also:

• Constant Field Values

Constructor Details

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 Details

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.

setMaxFullFlushMergeWaitMillis

public IndexWriterConfig setMaxFullFlushMergeWaitMillis(long maxFullFlushMergeWaitMillis)

Expert: sets the amount of time to wait for merges (during IndexWriter.commit() or IndexWriter.getReader(boolean, boolean)) returned by MergePolicy.findFullFlushMerges(...). If this time is reached, we proceed with the commit based on segments merged up to that point. The merges are not aborted, and will still run to completion independent of the commit or getReader call, like natural segment merges. The default is 0L.

Note: This settings has no effect unless MergePolicy.findFullFlushMerges(MergeTrigger, SegmentInfos, MergePolicy.MergeContext) has an implementation that actually returns merges which by default doesn't return any merges.

setIndexSort

public IndexWriterConfig setIndexSort(Sort sort)

Set the Sort order to use for all (flushed and merged) segments.

setLeafSorter

public IndexWriterConfig setLeafSorter(Comparator<LeafReader> leafSorter)

Set the comparator for sorting leaf readers. A DirectoryReader opened from a IndexWriter with this configuration will have its leaf readers sorted with the provided leaf sorter.

Parameters:

leafSorter - – a comparator for sorting leaf readers

Returns:

IndexWriterConfig with leafSorter set.

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()

setIndexWriterEventListener

public IndexWriterConfig setIndexWriterEventListener(IndexWriterEventListener eventListener)

Set event listener to record key events in IndexWriter