org.apache.hadoop.hbase

Enum MemoryCompactionPolicy

java.lang.Object

java.lang.Enum<MemoryCompactionPolicy>

org.apache.hadoop.hbase.MemoryCompactionPolicy

All Implemented Interfaces:

Serializable, Comparable<MemoryCompactionPolicy>

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

Enum describing all possible memory compaction policies

Enum Constant Summary

Enum Constants

Enum Constant and Description
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

Method Summary

Modifier and Type	Method and Description
static MemoryCompactionPolicy	valueOf(String name) Returns the enum constant of this type with the specified name.
static MemoryCompactionPolicy[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

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

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

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.

Method Detail

values

public static MemoryCompactionPolicy[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

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

Returns:

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

valueOf

public static MemoryCompactionPolicy valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (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 type has no constant with the specified name

NullPointerException - if the argument is null