Package org.apache.lucene.index
Class LogByteSizeMergePolicy
- java.lang.Object
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- org.apache.lucene.index.MergePolicy
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- org.apache.lucene.index.LogMergePolicy
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- org.apache.lucene.index.LogByteSizeMergePolicy
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- All Implemented Interfaces:
Closeable
,AutoCloseable
,Cloneable
public class LogByteSizeMergePolicy extends LogMergePolicy
This is aLogMergePolicy
that measures size of a segment as the total byte size of the segment's files.
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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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Field Summary
Fields Modifier and Type Field Description static double
DEFAULT_MAX_MERGE_MB
Default maximum segment size.static double
DEFAULT_MAX_MERGE_MB_FOR_FORCED_MERGE
Default maximum segment size.static double
DEFAULT_MIN_MERGE_MB
Default minimum segment size.-
Fields inherited from class org.apache.lucene.index.LogMergePolicy
calibrateSizeByDeletes, DEFAULT_MAX_MERGE_DOCS, DEFAULT_MERGE_FACTOR, DEFAULT_NO_CFS_RATIO, LEVEL_LOG_SPAN, maxMergeDocs, maxMergeSize, maxMergeSizeForForcedMerge, mergeFactor, minMergeSize
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Fields inherited from class org.apache.lucene.index.MergePolicy
DEFAULT_MAX_CFS_SEGMENT_SIZE, maxCFSSegmentSize, noCFSRatio, writer
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Constructor Summary
Constructors Constructor Description LogByteSizeMergePolicy()
Sole constructor, setting all settings to their defaults.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description double
getMaxMergeMB()
Returns the largest segment (measured by total byte size of the segment's files, in MB) that may be merged with other segments.double
getMaxMergeMBForForcedMerge()
Returns the largest segment (measured by total byte size of the segment's files, in MB) that may be merged with other segments during forceMerge.double
getMinMergeMB()
Get the minimum size for a segment to remain un-merged.void
setMaxMergeMB(double mb)
Determines the largest segment (measured by total byte size of the segment's files, in MB) that may be merged with other segments.void
setMaxMergeMBForForcedMerge(double mb)
Determines the largest segment (measured by total byte size of the segment's files, in MB) that may be merged with other segments during forceMerge.void
setMinMergeMB(double mb)
Sets the minimum size for the lowest level segments.protected long
size(SegmentCommitInfo info)
Return the byte size of the providedSegmentCommitInfo
, pro-rated by percentage of non-deleted documents is set.-
Methods inherited from class org.apache.lucene.index.LogMergePolicy
close, findForcedDeletesMerges, findForcedMerges, findMerges, getCalibrateSizeByDeletes, getMaxMergeDocs, getMergeFactor, isMerged, message, setCalibrateSizeByDeletes, setMaxMergeDocs, setMergeFactor, sizeBytes, sizeDocs, toString, verbose
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Methods inherited from class org.apache.lucene.index.MergePolicy
clone, getMaxCFSSegmentSizeMB, getNoCFSRatio, isMerged, setIndexWriter, setMaxCFSSegmentSizeMB, setNoCFSRatio, useCompoundFile
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Field Detail
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DEFAULT_MIN_MERGE_MB
public static final double DEFAULT_MIN_MERGE_MB
Default minimum segment size. @see setMinMergeMB- See Also:
- Constant Field Values
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DEFAULT_MAX_MERGE_MB
public static final double DEFAULT_MAX_MERGE_MB
Default maximum segment size. A segment of this size or larger will never be merged. @see setMaxMergeMB- See Also:
- Constant Field Values
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DEFAULT_MAX_MERGE_MB_FOR_FORCED_MERGE
public static final double DEFAULT_MAX_MERGE_MB_FOR_FORCED_MERGE
Default maximum segment size. A segment of this size or larger will never be merged during forceMerge. @see setMaxMergeMBForForceMerge- See Also:
- Constant Field Values
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Method Detail
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size
protected long size(SegmentCommitInfo info) throws IOException
Description copied from class:MergePolicy
Return the byte size of the providedSegmentCommitInfo
, pro-rated by percentage of non-deleted documents is set.- Overrides:
size
in classMergePolicy
- Throws:
IOException
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setMaxMergeMB
public void setMaxMergeMB(double mb)
Determines the largest segment (measured by total byte size of the segment's files, in MB) that may be merged with other segments. Small values (e.g., less than 50 MB) are best for interactive indexing, as this limits the length of pauses while indexing to a few seconds. Larger values are best for batched indexing and speedier searches.
Note that
LogMergePolicy.setMaxMergeDocs(int)
is also used to check whether a segment is too large for merging (it's either or).
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getMaxMergeMB
public double getMaxMergeMB()
Returns the largest segment (measured by total byte size of the segment's files, in MB) that may be merged with other segments.- See Also:
setMaxMergeMB(double)
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setMaxMergeMBForForcedMerge
public void setMaxMergeMBForForcedMerge(double mb)
Determines the largest segment (measured by total byte size of the segment's files, in MB) that may be merged with other segments during forceMerge. Setting it low will leave the index with more than 1 segment, even if
IndexWriter.forceMerge(int)
is called.
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getMaxMergeMBForForcedMerge
public double getMaxMergeMBForForcedMerge()
Returns the largest segment (measured by total byte size of the segment's files, in MB) that may be merged with other segments during forceMerge.- See Also:
setMaxMergeMBForForcedMerge(double)
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setMinMergeMB
public void setMinMergeMB(double mb)
Sets the minimum size for the lowest level segments. Any segments below this size are considered to be on the same level (even if they vary drastically in size) and will be merged whenever there are mergeFactor of them. This effectively truncates the "long tail" of small segments that would otherwise be created into a single level. If you set this too large, it could greatly increase the merging cost during indexing (if you flush many small segments).
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getMinMergeMB
public double getMinMergeMB()
Get the minimum size for a segment to remain un-merged.- See Also:
setMinMergeMB(double)
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