org.rocksdb

Class CompactionOptionsUniversal

java.lang.Object

org.rocksdb.AbstractNativeReference

org.rocksdb.AbstractImmutableNativeReference

org.rocksdb.RocksObject

org.rocksdb.CompactionOptionsUniversal

All Implemented Interfaces:

java.lang.AutoCloseable

public class CompactionOptionsUniversal
extends RocksObject

Options for Universal Compaction

Field Summary

Fields inherited from class org.rocksdb.RocksObject

nativeHandle_

Constructor Summary

Constructors

Constructor and Description
CompactionOptionsUniversal()

Method Summary

Modifier and Type	Method and Description
boolean	allowTrivialMove() Option to optimize the universal multi level compaction by enabling trivial move for non overlapping files.
int	compressionSizePercent() If this option is set to be -1 (the default value), all the output files will follow compression type specified.
protected void	disposeInternal(long handle)
int	maxMergeWidth() The maximum number of files in a single compaction run.
int	maxSizeAmplificationPercent() The size amplification is defined as the amount (in percentage) of additional storage needed to store a single byte of data in the database.
int	minMergeWidth() The minimum number of files in a single compaction run.
CompactionOptionsUniversal	setAllowTrivialMove(boolean allowTrivialMove) Option to optimize the universal multi level compaction by enabling trivial move for non overlapping files.
CompactionOptionsUniversal	setCompressionSizePercent(int compressionSizePercent) If this option is set to be -1 (the default value), all the output files will follow compression type specified.
CompactionOptionsUniversal	setMaxMergeWidth(int maxMergeWidth) The maximum number of files in a single compaction run.
CompactionOptionsUniversal	setMaxSizeAmplificationPercent(int maxSizeAmplificationPercent) The size amplification is defined as the amount (in percentage) of additional storage needed to store a single byte of data in the database.
CompactionOptionsUniversal	setMinMergeWidth(int minMergeWidth) The minimum number of files in a single compaction run.
CompactionOptionsUniversal	setSizeRatio(int sizeRatio) Percentage flexibility while comparing file size.
CompactionOptionsUniversal	setStopStyle(CompactionStopStyle compactionStopStyle) The algorithm used to stop picking files into a single compaction run Default: CompactionStopStyle.CompactionStopStyleTotalSize
int	sizeRatio() Percentage flexibility while comparing file size.
CompactionStopStyle	stopStyle() The algorithm used to stop picking files into a single compaction run Default: CompactionStopStyle.CompactionStopStyleTotalSize

Methods inherited from class org.rocksdb.RocksObject

disposeInternal

Methods inherited from class org.rocksdb.AbstractImmutableNativeReference

close, disOwnNativeHandle, isOwningHandle

Methods inherited from class org.rocksdb.AbstractNativeReference

dispose, finalize

Methods inherited from class java.lang.Object

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

Constructor Detail

CompactionOptionsUniversal

public CompactionOptionsUniversal()

Method Detail

setSizeRatio

public CompactionOptionsUniversal setSizeRatio(int sizeRatio)

Percentage flexibility while comparing file size. If the candidate file(s) size is 1% smaller than the next file's size, then include next file into this candidate set. Default: 1

Parameters:

sizeRatio - The size ratio to use

Returns:

the reference to the current options.

sizeRatio

public int sizeRatio()

Percentage flexibility while comparing file size. If the candidate file(s) size is 1% smaller than the next file's size, then include next file into this candidate set. Default: 1

Returns:

The size ratio in use

setMinMergeWidth

public CompactionOptionsUniversal setMinMergeWidth(int minMergeWidth)

The minimum number of files in a single compaction run. Default: 2

Parameters:

minMergeWidth - minimum number of files in a single compaction run

Returns:

the reference to the current options.

minMergeWidth

public int minMergeWidth()

The minimum number of files in a single compaction run. Default: 2

Returns:

minimum number of files in a single compaction run

setMaxMergeWidth

public CompactionOptionsUniversal setMaxMergeWidth(int maxMergeWidth)

The maximum number of files in a single compaction run. Default: Long.MAX_VALUE

Parameters:

maxMergeWidth - maximum number of files in a single compaction run

Returns:

the reference to the current options.

maxMergeWidth

public int maxMergeWidth()

The maximum number of files in a single compaction run. Default: Long.MAX_VALUE

Returns:

maximum number of files in a single compaction run

setMaxSizeAmplificationPercent

public CompactionOptionsUniversal setMaxSizeAmplificationPercent(int maxSizeAmplificationPercent)

The size amplification is defined as the amount (in percentage) of additional storage needed to store a single byte of data in the database. For example, a size amplification of 2% means that a database that contains 100 bytes of user-data may occupy upto 102 bytes of physical storage. By this definition, a fully compacted database has a size amplification of 0%. Rocksdb uses the following heuristic to calculate size amplification: it assumes that all files excluding the earliest file contribute to the size amplification. Default: 200, which means that a 100 byte database could require upto 300 bytes of storage.

Parameters:

maxSizeAmplificationPercent - the amount of additional storage needed (as a percentage) to store a single byte in the database

Returns:

the reference to the current options.

maxSizeAmplificationPercent

public int maxSizeAmplificationPercent()

The size amplification is defined as the amount (in percentage) of additional storage needed to store a single byte of data in the database. For example, a size amplification of 2% means that a database that contains 100 bytes of user-data may occupy upto 102 bytes of physical storage. By this definition, a fully compacted database has a size amplification of 0%. Rocksdb uses the following heuristic to calculate size amplification: it assumes that all files excluding the earliest file contribute to the size amplification. Default: 200, which means that a 100 byte database could require upto 300 bytes of storage.

Returns:

the amount of additional storage needed (as a percentage) to store a single byte in the database

setCompressionSizePercent

public CompactionOptionsUniversal setCompressionSizePercent(int compressionSizePercent)

If this option is set to be -1 (the default value), all the output files will follow compression type specified. If this option is not negative, we will try to make sure compressed size is just above this value. In normal cases, at least this percentage of data will be compressed. When we are compacting to a new file, here is the criteria whether it needs to be compressed: assuming here are the list of files sorted by generation time: A1...An B1...Bm C1...Ct where A1 is the newest and Ct is the oldest, and we are going to compact B1...Bm, we calculate the total size of all the files as total_size, as well as the total size of C1...Ct as total_C, the compaction output file will be compressed iff total_C / total_size < this percentage Default: -1

Parameters:

compressionSizePercent - percentage of size for compression

Returns:

the reference to the current options.

compressionSizePercent

public int compressionSizePercent()

If this option is set to be -1 (the default value), all the output files will follow compression type specified. If this option is not negative, we will try to make sure compressed size is just above this value. In normal cases, at least this percentage of data will be compressed. When we are compacting to a new file, here is the criteria whether it needs to be compressed: assuming here are the list of files sorted by generation time: A1...An B1...Bm C1...Ct where A1 is the newest and Ct is the oldest, and we are going to compact B1...Bm, we calculate the total size of all the files as total_size, as well as the total size of C1...Ct as total_C, the compaction output file will be compressed iff total_C / total_size < this percentage Default: -1

Returns:

percentage of size for compression

setStopStyle

public CompactionOptionsUniversal setStopStyle(CompactionStopStyle compactionStopStyle)

The algorithm used to stop picking files into a single compaction run Default: CompactionStopStyle.CompactionStopStyleTotalSize

Parameters:

compactionStopStyle - The compaction algorithm

Returns:

the reference to the current options.

stopStyle

public CompactionStopStyle stopStyle()

The algorithm used to stop picking files into a single compaction run Default: CompactionStopStyle.CompactionStopStyleTotalSize

Returns:

The compaction algorithm

setAllowTrivialMove

public CompactionOptionsUniversal setAllowTrivialMove(boolean allowTrivialMove)

Option to optimize the universal multi level compaction by enabling trivial move for non overlapping files. Default: false

Parameters:

allowTrivialMove - true if trivial move is allowed

Returns:

the reference to the current options.

allowTrivialMove

public boolean allowTrivialMove()

Option to optimize the universal multi level compaction by enabling trivial move for non overlapping files. Default: false

Returns:

true if trivial move is allowed

disposeInternal

protected final void disposeInternal(long handle)

Specified by:

disposeInternal in class RocksObject