public class

LogByteSizeMergePolicy

extends LogMergePolicy
java.lang.Object
   ↳ org.apache.lucene.index.MergePolicy
     ↳ org.apache.lucene.index.LogMergePolicy
       ↳ org.apache.lucene.index.LogByteSizeMergePolicy
Known Direct Subclasses

Class Overview

This is a LogMergePolicy that measures size of a segment as the total byte size of the segment's files.

Summary

Constants
double DEFAULT_MAX_MERGE_MB Default maximum segment size.
double DEFAULT_MAX_MERGE_MB_FOR_OPTIMIZE Default maximum segment size.
double DEFAULT_MIN_MERGE_MB Default minimum segment size.
[Expand]
Inherited Constants
From class org.apache.lucene.index.LogMergePolicy
[Expand]
Inherited Fields
From class org.apache.lucene.index.LogMergePolicy
From class org.apache.lucene.index.MergePolicy
Public Constructors
LogByteSizeMergePolicy()
Public Methods
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 getMaxMergeMBForOptimize()
Returns the largest segment (measured by total byte size of the segment's files, in MB) that may be merged with other segments during optimize.
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 setMaxMergeMBForOptimize(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 optimize.

void setMinMergeMB(double mb)
Sets the minimum size for the lowest level segments.
Protected Methods
long size(SegmentInfo info)
[Expand]
Inherited Methods
From class org.apache.lucene.index.LogMergePolicy
From class org.apache.lucene.index.MergePolicy
From class java.lang.Object
From interface java.io.Closeable

Constants

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

Constant Value: 2048.0

public static final double DEFAULT_MAX_MERGE_MB_FOR_OPTIMIZE

Default maximum segment size. A segment of this size or larger will never be merged during optimize. @see setMaxMergeMBForOptimize

Constant Value: 9.223372036854776E18

public static final double DEFAULT_MIN_MERGE_MB

Default minimum segment size. @see setMinMergeMB

Constant Value: 1.6

Public Constructors

public LogByteSizeMergePolicy ()

Public Methods

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.

public double getMaxMergeMBForOptimize ()

Returns the largest segment (measured by total byte size of the segment's files, in MB) that may be merged with other segments during optimize.

public double getMinMergeMB ()

Get the minimum size for a segment to remain un-merged.

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 setMaxMergeDocs(int) is also used to check whether a segment is too large for merging (it's either or).

public void setMaxMergeMBForOptimize (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 optimize. Setting it low will leave the index with more than 1 segment, even if optimize() is called.

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).

Protected Methods

protected long size (SegmentInfo info)

Throws
IOException