CompactionOptionsUniversal

java.lang.Object
- org.rocksdb.AbstractNativeReference
- - org.rocksdb.AbstractImmutableNativeReference
  - - org.rocksdb.RocksObject
    - - org.rocksdb.CompactionOptionsUniversal

所有已实现的接口:

java.lang.AutoCloseable
```
public class CompactionOptionsUniversal
extends RocksObject
```
Options for Universal Compaction

字段概要
- 从类继承的字段 org.rocksdb.RocksObject
  nativeHandle_
- 从类继承的字段 org.rocksdb.AbstractImmutableNativeReference
  owningHandle_

构造器概要

构造器
构造器和说明

CompactionOptionsUniversal()

构造器
构造器和说明
`CompactionOptionsUniversal()`

方法概要

所有方法实例方法具体方法
限定符和类型	方法和说明
`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`

从类继承的方法 org.rocksdb.RocksObject
disposeInternal, getNativeHandle

从类继承的方法 org.rocksdb.AbstractImmutableNativeReference
close, disOwnNativeHandle, isOwningHandle

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 构造器详细资料
  - CompactionOptionsUniversal
```
public CompactionOptionsUniversal()
```
- 方法详细资料
  - 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
    
    参数:
    
    sizeRatio - The size ratio to use
    
    返回:
    
    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
    
    返回:
    
    The size ratio in use
  - setMinMergeWidth
```
public CompactionOptionsUniversal setMinMergeWidth(int minMergeWidth)
```
    The minimum number of files in a single compaction run.
    Default: 2
    
    参数:
    
    minMergeWidth - minimum number of files in a single compaction run
    
    返回:
    
    the reference to the current options.
  - minMergeWidth
```
public int minMergeWidth()
```
    The minimum number of files in a single compaction run.
    Default: 2
    
    返回:
    
    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
    
    参数:
    
    maxMergeWidth - maximum number of files in a single compaction run
    
    返回:
    
    the reference to the current options.
  - maxMergeWidth
```
public int maxMergeWidth()
```
    The maximum number of files in a single compaction run.
    Default: Long.MAX_VALUE
    
    返回:
    
    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.
    
    参数:
    
    maxSizeAmplificationPercent - the amount of additional storage needed (as a percentage) to store a single byte in the database
    
    返回:
    
    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.
    
    返回:
    
    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
    
    参数:
    
    compressionSizePercent - percentage of size for compression
    
    返回:
    
    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
    
    返回:
    
    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
    
    参数:
    
    compactionStopStyle - The compaction algorithm
    
    返回:
    
    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
    
    返回:
    
    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
    
    参数:
    
    allowTrivialMove - true if trivial move is allowed
    
    返回:
    
    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
    
    返回:
    
    true if trivial move is allowed
  - disposeInternal
```
protected final void disposeInternal(long handle)
```
    指定者:
    
    disposeInternal 在类中 RocksObject

类 CompactionOptionsUniversal

字段概要

从类继承的字段 org.rocksdb.RocksObject

从类继承的字段 org.rocksdb.AbstractImmutableNativeReference

构造器概要

方法概要

从类继承的方法 org.rocksdb.RocksObject

从类继承的方法 org.rocksdb.AbstractImmutableNativeReference

从类继承的方法 java.lang.Object

构造器详细资料

CompactionOptionsUniversal

方法详细资料

setSizeRatio

sizeRatio

setMinMergeWidth

minMergeWidth

setMaxMergeWidth

maxMergeWidth

setMaxSizeAmplificationPercent

maxSizeAmplificationPercent

setCompressionSizePercent

compressionSizePercent

setStopStyle

stopStyle

setAllowTrivialMove

allowTrivialMove

disposeInternal