Package org.rocksdb

Class CompactionOptionsUniversal

java.lang.Object
org.rocksdb.AbstractNativeReference
org.rocksdb.AbstractImmutableNativeReference
org.rocksdb.RocksObject
org.rocksdb.CompactionOptionsUniversal
All Implemented Interfaces:
AutoCloseable
public class CompactionOptionsUniversal extends RocksObject
Options for Universal Compaction

  • Constructor Details

    • CompactionOptionsUniversal

      public CompactionOptionsUniversal()

  • Method Details

    • 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

      Parameters:
      sizeRatio - The size ratio to use
      Returns:
      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

      Returns:
      The size ratio in use

    • setMinMergeWidth

      public CompactionOptionsUniversal setMinMergeWidth(int minMergeWidth)
      The minimum number of files in a single compaction run.

      Default: 2

      Parameters:
      minMergeWidth - minimum number of files in a single compaction run
      Returns:
      the reference to the current options.

    • minMergeWidth

      public int minMergeWidth()
      The minimum number of files in a single compaction run.

      Default: 2

      Returns:
      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

      Parameters:
      maxMergeWidth - maximum number of files in a single compaction run
      Returns:
      the reference to the current options.

    • maxMergeWidth

      public int maxMergeWidth()
      The maximum number of files in a single compaction run.

      Default: Long.MAX_VALUE

      Returns:
      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.

      Parameters:
      maxSizeAmplificationPercent - the amount of additional storage needed (as a percentage) to store a single byte in the database
      Returns:
      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.

      Returns:
      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

      Parameters:
      compressionSizePercent - percentage of size for compression
      Returns:
      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

      Returns:
      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

      Parameters:
      compactionStopStyle - The compaction algorithm
      Returns:
      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

      Returns:
      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

      Parameters:
      allowTrivialMove - true if trivial move is allowed
      Returns:
      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

      Returns:
      true if trivial move is allowed

    • disposeInternal

      protected final void disposeInternal(long handle)
      Specified by:
      disposeInternal in class RocksObject