class ShardingKeyIndex[K] extends KeyIndex[K]

An example of a generic KeyIndex which accounts for sharding that could occur in a data store like Apache Accumulo. Given a shard count (pre-configured), this index adds a "shard prefix" to the true index as given by the inner argument. Accumulo can shard based off of the first digit of a row ID, and since we use a round-robin approach to generate prefixes, this distributes spatially close indices across different shards, and thus helps avoid hot spots.

Assumptions

  • The given shard count will be between 1 and 8.
  • The inner index will produce a value less than 2^60 for any given key.
Linear Supertypes
KeyIndex[K], Serializable, Serializable, AnyRef, Any
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Inherited
  1. ShardingKeyIndex
  2. KeyIndex
  3. Serializable
  4. Serializable
  5. AnyRef
  6. Any
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Visibility
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Instance Constructors

  1. new ShardingKeyIndex(inner: KeyIndex[K], shardCount: Int)

Value Members

  1. def indexRanges(keyRange: (K, K)): Seq[(BigInt, BigInt)]
    Definition Classes
    ShardingKeyIndex → KeyIndex
  2. val inner: KeyIndex[K]
  3. def keyBounds: KeyBounds[K]

    Some(keybounds) if the indexed space is bounded; None if it is unbounded

    Some(keybounds) if the indexed space is bounded; None if it is unbounded

    Definition Classes
    ShardingKeyIndex → KeyIndex
  4. val shardCount: Int
  5. def toIndex(key: K): BigInt
    Definition Classes
    ShardingKeyIndex → KeyIndex