org.rocksdb

枚举 CompactionPriority

java.lang.Object

java.lang.Enum<CompactionPriority>

org.rocksdb.CompactionPriority

所有已实现的接口:

java.io.Serializable, java.lang.Comparable<CompactionPriority>

public enum CompactionPriority
extends java.lang.Enum<CompactionPriority>

Compaction Priorities

枚举常量概要

枚举常量

枚举常量和说明
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.

方法概要

限定符和类型	方法和说明
static CompactionPriority	getCompactionPriority(byte value) Get CompactionPriority by byte value.
byte	getValue() Returns the byte value of the enumerations value
static CompactionPriority	valueOf(java.lang.String name) 返回带有指定名称的该类型的枚举常量。
static CompactionPriority[]	values() 按照声明该枚举类型的常量的顺序, 返回 包含这些常量的数组。

从类继承的方法 java.lang.Enum

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

从类继承的方法 java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

枚举常量详细资料

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.

方法详细资料

values

public static CompactionPriority[] values()

按照声明该枚举类型的常量的顺序, 返回 包含这些常量的数组。该方法可用于迭代 常量, 如下所示:

for (CompactionPriority c : CompactionPriority.values())
    System.out.println(c);

返回:

按照声明该枚举类型的常量的顺序返回的包含这些常量的数组

valueOf

public static CompactionPriority valueOf(java.lang.String name)

返回带有指定名称的该类型的枚举常量。 字符串必须与用于声明该类型的枚举常量的 标识符完全匹配。(不允许有多余 的空格字符。)

参数:

name - 要返回的枚举常量的名称。

返回:

返回带有指定名称的枚举常量

抛出:

java.lang.IllegalArgumentException - 如果该枚举类型没有带有指定名称的常量

java.lang.NullPointerException - 如果参数为空值

getValue

public byte getValue()

Returns the byte value of the enumerations value

返回:

byte representation

getCompactionPriority

public static CompactionPriority getCompactionPriority(byte value)

Get CompactionPriority by byte value.

参数:

value - byte representation of CompactionPriority.

返回:

CompactionPriority instance or null.

抛出:

java.lang.IllegalArgumentException - if an invalid value is provided.