DbConstants

java.lang.Object

org.iq80.leveldb.impl.DbConstants

public final class DbConstants extends Object

Field Summary

Fields

Modifier and Type

Field

Description

static final int

L0_COMPACTION_TRIGGER

Level-0 compaction is started when we hit this many files.

static final int

L0_SLOWDOWN_WRITES_TRIGGER

Soft limit on number of level-0 files.

static final int

L0_STOP_WRITES_TRIGGER

Maximum number of level-0 files.

static final int

MAJOR_VERSION

static final int

MAX_MEM_COMPACT_LEVEL

Maximum level to which a new compacted memtable is pushed if it does not create overlap.

static final int

MINOR_VERSION

static final int

NUM_LEVELS

Max number of levels
Constructor Summary

Constructors

Modifier

Constructor

Description

private

DbConstants()
Method Summary

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details
- MAJOR_VERSION
  
  public static final int MAJOR_VERSION
  See Also:
  
  Constant Field Values
- MINOR_VERSION
  
  public static final int MINOR_VERSION
  See Also:
  
  Constant Field Values
- NUM_LEVELS
  
  public static final int NUM_LEVELS
  
  Max number of levels
  See Also:
  
  Constant Field Values
- L0_COMPACTION_TRIGGER
  
  public static final int L0_COMPACTION_TRIGGER
  
  Level-0 compaction is started when we hit this many files.
  See Also:
  
  Constant Field Values
- L0_SLOWDOWN_WRITES_TRIGGER
  
  public static final int L0_SLOWDOWN_WRITES_TRIGGER
  
  Soft limit on number of level-0 files. We slow down writes at this point.
  See Also:
  
  Constant Field Values
- L0_STOP_WRITES_TRIGGER
  
  public static final int L0_STOP_WRITES_TRIGGER
  
  Maximum number of level-0 files. We stop writes at this point.
  See Also:
  
  Constant Field Values
- MAX_MEM_COMPACT_LEVEL
  
  public static final int MAX_MEM_COMPACT_LEVEL
  
  Maximum level to which a new compacted memtable is pushed if it does not create overlap. We try to push to level 2 to avoid the relatively expensive level 0=>1 compactions and to avoid some expensive manifest file operations. We do not push all the way to the largest level since that can generate a lot of wasted disk space if the same key space is being repeatedly overwritten.
  See Also:
  
  Constant Field Values
Constructor Details
- DbConstants
  
  private DbConstants()