Package org.apache.lucene.index
Class UpgradeIndexMergePolicy
- java.lang.Object
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- org.apache.lucene.index.MergePolicy
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- org.apache.lucene.index.UpgradeIndexMergePolicy
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- All Implemented Interfaces:
java.io.Closeable
,java.lang.AutoCloseable
,java.lang.Cloneable
public class UpgradeIndexMergePolicy extends MergePolicy
ThisMergePolicy
is used for upgrading all existing segments of an index when callingIndexWriter.forceMerge(int)
. All other methods delegate to the baseMergePolicy
given to the constructor. This allows for an as-cheap-as possible upgrade of an older index by only upgrading segments that are created by previous Lucene versions. forceMerge does no longer really merge; it is just used to "forceMerge" older segment versions away.In general one would use
IndexUpgrader
, but for a fully customizeable upgrade, you can use this like any otherMergePolicy
and callIndexWriter.forceMerge(int)
:IndexWriterConfig iwc = new IndexWriterConfig(Version.LUCENE_XX, new KeywordAnalyzer()); iwc.setMergePolicy(new UpgradeIndexMergePolicy(iwc.getMergePolicy())); IndexWriter w = new IndexWriter(dir, iwc); w.forceMerge(1); w.close();
Warning: This merge policy may reorder documents if the index was partially upgraded before calling forceMerge (e.g., documents were added). If your application relies on "monotonicity" of doc IDs (which means that the order in which the documents were added to the index is preserved), do a forceMerge(1) instead. Please note, the delegate
MergePolicy
may also reorder documents.- See Also:
IndexUpgrader
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Nested Class Summary
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Nested classes/interfaces inherited from class org.apache.lucene.index.MergePolicy
MergePolicy.DocMap, MergePolicy.MergeAbortedException, MergePolicy.MergeException, MergePolicy.MergeSpecification, MergePolicy.MergeTrigger, MergePolicy.OneMerge
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Constructor Summary
Constructors Constructor Description UpgradeIndexMergePolicy(MergePolicy base)
Wrap the givenMergePolicy
and intercept forceMerge requests to only upgrade segments written with previous Lucene versions.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
close()
Release all resources for the policy.MergePolicy.MergeSpecification
findForcedDeletesMerges(SegmentInfos segmentInfos)
Determine what set of merge operations is necessary in order to expunge all deletes from the index.MergePolicy.MergeSpecification
findForcedMerges(SegmentInfos segmentInfos, int maxSegmentCount, java.util.Map<SegmentCommitInfo,java.lang.Boolean> segmentsToMerge)
Determine what set of merge operations is necessary in order to merge to <= the specified segment count.MergePolicy.MergeSpecification
findMerges(MergePolicy.MergeTrigger mergeTrigger, SegmentInfos segmentInfos)
Determine what set of merge operations are now necessary on the index.void
setIndexWriter(IndexWriter writer)
Sets theIndexWriter
to use by this merge policy.java.lang.String
toString()
boolean
useCompoundFile(SegmentInfos segments, SegmentCommitInfo newSegment)
Returns true if a new segment (regardless of its origin) should use the compound file format.-
Methods inherited from class org.apache.lucene.index.MergePolicy
clone, getMaxCFSSegmentSizeMB, getNoCFSRatio, setMaxCFSSegmentSizeMB, setNoCFSRatio
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Constructor Detail
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UpgradeIndexMergePolicy
public UpgradeIndexMergePolicy(MergePolicy base)
Wrap the givenMergePolicy
and intercept forceMerge requests to only upgrade segments written with previous Lucene versions.
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Method Detail
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setIndexWriter
public void setIndexWriter(IndexWriter writer)
Description copied from class:MergePolicy
Sets theIndexWriter
to use by this merge policy. This method is allowed to be called only once, and is usually set by IndexWriter. If it is called more than once,SetOnce.AlreadySetException
is thrown.- Overrides:
setIndexWriter
in classMergePolicy
- See Also:
SetOnce
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findMerges
public MergePolicy.MergeSpecification findMerges(MergePolicy.MergeTrigger mergeTrigger, SegmentInfos segmentInfos) throws java.io.IOException
Description copied from class:MergePolicy
Determine what set of merge operations are now necessary on the index.IndexWriter
calls this whenever there is a change to the segments. This call is always synchronized on theIndexWriter
instance so only one thread at a time will call this method.- Specified by:
findMerges
in classMergePolicy
- Parameters:
mergeTrigger
- the event that triggered the mergesegmentInfos
- the total set of segments in the index- Throws:
java.io.IOException
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findForcedMerges
public MergePolicy.MergeSpecification findForcedMerges(SegmentInfos segmentInfos, int maxSegmentCount, java.util.Map<SegmentCommitInfo,java.lang.Boolean> segmentsToMerge) throws java.io.IOException
Description copied from class:MergePolicy
Determine what set of merge operations is necessary in order to merge to <= the specified segment count.IndexWriter
calls this when itsIndexWriter.forceMerge(int)
method is called. This call is always synchronized on theIndexWriter
instance so only one thread at a time will call this method.- Specified by:
findForcedMerges
in classMergePolicy
- Parameters:
segmentInfos
- the total set of segments in the indexmaxSegmentCount
- requested maximum number of segments in the index (currently this is always 1)segmentsToMerge
- contains the specific SegmentInfo instances that must be merged away. This may be a subset of all SegmentInfos. If the value is True for a given SegmentInfo, that means this segment was an original segment present in the to-be-merged index; else, it was a segment produced by a cascaded merge.- Throws:
java.io.IOException
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findForcedDeletesMerges
public MergePolicy.MergeSpecification findForcedDeletesMerges(SegmentInfos segmentInfos) throws java.io.IOException
Description copied from class:MergePolicy
Determine what set of merge operations is necessary in order to expunge all deletes from the index.- Specified by:
findForcedDeletesMerges
in classMergePolicy
- Parameters:
segmentInfos
- the total set of segments in the index- Throws:
java.io.IOException
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useCompoundFile
public boolean useCompoundFile(SegmentInfos segments, SegmentCommitInfo newSegment) throws java.io.IOException
Description copied from class:MergePolicy
Returns true if a new segment (regardless of its origin) should use the compound file format. The default implementation returnstrue
iff the size of the given mergedInfo is less or equal toMergePolicy.getMaxCFSSegmentSizeMB()
and the size is less or equal to the TotalIndexSize *MergePolicy.getNoCFSRatio()
otherwisefalse
.- Overrides:
useCompoundFile
in classMergePolicy
- Throws:
java.io.IOException
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close
public void close()
Description copied from class:MergePolicy
Release all resources for the policy.- Specified by:
close
in interfacejava.lang.AutoCloseable
- Specified by:
close
in interfacejava.io.Closeable
- Specified by:
close
in classMergePolicy
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toString
public java.lang.String toString()
- Overrides:
toString
in classjava.lang.Object
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