org.apache.hadoop.hbase

枚举 MemoryCompactionPolicy

java.lang.Object

java.lang.Enum<MemoryCompactionPolicy>

org.apache.hadoop.hbase.MemoryCompactionPolicy

所有已实现的接口:

Serializable, Comparable<MemoryCompactionPolicy>

@InterfaceAudience.Public
public enum MemoryCompactionPolicy
extends Enum<MemoryCompactionPolicy>

Enum describing all possible memory compaction policies

枚举常量概要

枚举常量

枚举常量和说明
ADAPTIVE Adaptive compaction adapts to the workload.
BASIC Basic policy applies optimizations which modify the index to a more compacted representation.
EAGER In addition to compacting the index representation as the basic policy, eager policy eliminates duplication while the data is still in memory (much like the on-disk compaction does after the data is flushed to disk).
NONE No memory compaction, when size threshold is exceeded data is flushed to disk

方法概要

限定符和类型	方法和说明
static MemoryCompactionPolicy	valueOf(String name) 返回带有指定名称的该类型的枚举常量。
static MemoryCompactionPolicy[]	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

NONE

public static final MemoryCompactionPolicy NONE

No memory compaction, when size threshold is exceeded data is flushed to disk

BASIC

public static final MemoryCompactionPolicy BASIC

Basic policy applies optimizations which modify the index to a more compacted representation. This is beneficial in all access patterns. The smaller the cells are the greater the benefit of this policy. This is the default policy.

EAGER

public static final MemoryCompactionPolicy EAGER

In addition to compacting the index representation as the basic policy, eager policy eliminates duplication while the data is still in memory (much like the on-disk compaction does after the data is flushed to disk). This policy is most useful for applications with high data churn or small working sets.

ADAPTIVE

public static final MemoryCompactionPolicy ADAPTIVE

Adaptive compaction adapts to the workload. It applies either index compaction or data compaction based on the ratio of duplicate cells in the data.

方法详细资料

values

public static MemoryCompactionPolicy[] 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 (MemoryCompactionPolicy c : MemoryCompactionPolicy.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 MemoryCompactionPolicy valueOf(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:

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

NullPointerException - 如果参数为空值