Package org.rocksdb

Enum IndexType

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Comparable<IndexType>
    public enum IndexType
extends java.lang.Enum<IndexType>
    IndexType used in conjunction with BlockBasedTable.

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description
      kBinarySearch
      A space efficient index block that is optimized for binary-search-based index.
      kBinarySearchWithFirstKey
      Like kBinarySearch, but index also contains first key of each block.
      kHashSearch
      The hash index, if enabled, will do the hash lookup when Options.prefix_extractor is provided.
      kTwoLevelIndexSearch
      A two-level index implementation.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      byte getValue()
      Returns the byte value of the enumerations value
      static IndexType valueOf​(java.lang.String name)
      Returns the enum constant of this type with the specified name.
      static IndexType[] 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

      • kBinarySearch

        public static final IndexType kBinarySearch
        A space efficient index block that is optimized for binary-search-based index.

      • kHashSearch

        public static final IndexType kHashSearch
        The hash index, if enabled, will do the hash lookup when Options.prefix_extractor is provided.

      • kTwoLevelIndexSearch

        public static final IndexType kTwoLevelIndexSearch
        A two-level index implementation. Both levels are binary search indexes.

      • kBinarySearchWithFirstKey

        public static final IndexType kBinarySearchWithFirstKey
        Like kBinarySearch, but index also contains first key of each block. This allows iterators to defer reading the block until it's actually needed. May significantly reduce read amplification of short range scans. Without it, iterator seek usually reads one block from each level-0 file and from each level, which may be expensive. Works best in combination with: - IndexShorteningMode::kNoShortening, - custom FlushBlockPolicy to cut blocks at some meaningful boundaries, e.g. when prefix changes. Makes the index significantly bigger (2x or more), especially when keys are long.

    • Method Detail

      • values

        public static IndexType[] 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 (IndexType c : IndexType.values())
    System.out.println(c);
        Returns:
        an array containing the constants of this enum type, in the order they are declared

      • valueOf

        public static IndexType valueOf​(java.lang.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:
        java.lang.IllegalArgumentException - if this enum type has no constant with the specified name
        java.lang.NullPointerException - if the argument is null

      • getValue

        public byte getValue()
        Returns the byte value of the enumerations value
        Returns:
        byte representation