Package org.rocksdb

Enum Class CompactionPriority

java.lang.Object

java.lang.Enum<CompactionPriority>

org.rocksdb.CompactionPriority

All Implemented Interfaces:

Serializable, Comparable<CompactionPriority>, Constable

public enum CompactionPriority
extends Enum<CompactionPriority>

Compaction Priorities

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Enum

Enum.EnumDesc<E extends Enum<E>>

Enum Constant Summary

Enum Constants

Enum Constant	Description
ByCompensatedSize	Slightly Prioritize larger files by size compensated by #deletes
MinOverlappingRatio	First compact files whose ratio between overlapping size in next level and its size is the smallest.
OldestLargestSeqFirst	First compact files whose data's latest update time is oldest.
OldestSmallestSeqFirst	First compact files whose range hasn't been compacted to the next level for the longest.
RoundRobin	Keeps a cursor(s) of the successor of the file (key range) was/were compacted before, and always picks the next files (key range) in that level.

Method Summary

Modifier and Type	Method	Description
static CompactionPriority	getCompactionPriority(byte value)	Get CompactionPriority by byte value.
byte	getValue()	Returns the byte value of the enumerations value
static CompactionPriority	valueOf(String name)	Returns the enum constant of this class with the specified name.
static CompactionPriority[]	values()	Returns an array containing the constants of this enum class, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, describeConstable, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Details

ByCompensatedSize

public static final CompactionPriority ByCompensatedSize

Slightly Prioritize larger files by size compensated by #deletes

OldestLargestSeqFirst

public static final CompactionPriority OldestLargestSeqFirst

First compact files whose data's latest update time is oldest. Try this if you only update some hot keys in small ranges.

OldestSmallestSeqFirst

public static final CompactionPriority OldestSmallestSeqFirst

First compact files whose range hasn't been compacted to the next level for the longest. If your updates are random across the key space, write amplification is slightly better with this option.

MinOverlappingRatio

public static final CompactionPriority MinOverlappingRatio

First compact files whose ratio between overlapping size in next level and its size is the smallest. It in many cases can optimize write amplification.

RoundRobin

public static final CompactionPriority RoundRobin

Keeps a cursor(s) of the successor of the file (key range) was/were compacted before, and always picks the next files (key range) in that level. The file picking process will cycle through all the files in a round-robin manner.

Method Details

values

public static CompactionPriority[] values()

Returns an array containing the constants of this enum class, in the order they are declared.

Returns:

an array containing the constants of this enum class, in the order they are declared

valueOf

public static CompactionPriority valueOf(String name)

Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum class has no constant with the specified name

NullPointerException - if the argument is null

getValue

public byte getValue()

Returns the byte value of the enumerations value

Returns:

byte representation

getCompactionPriority

public static CompactionPriority getCompactionPriority(byte value)

Get CompactionPriority by byte value.

Parameters:

value - byte representation of CompactionPriority.

Returns:

CompactionPriority instance or null.

Throws:

IllegalArgumentException - if an invalid value is provided.