KeysIndex (apache-cassandra API)
Date: 2014-10-21

org.apache.cassandra.db.index.keys

## Class KeysIndex

- java.lang.Object
- - org.apache.cassandra.db.index.SecondaryIndex
  - - org.apache.cassandra.db.index.PerColumnSecondaryIndex
    - - org.apache.cassandra.db.index.AbstractSimplePerColumnSecondaryIndex
      - - org.apache.cassandra.db.index.keys.KeysIndex

-     public class KeysIndex
      extends AbstractSimplePerColumnSecondaryIndex

  Implements a secondary index for a column family using a second column family. The design uses inverted index http://en.wikipedia.org/wiki/Inverted_index. The row key is the indexed value. For example, if we're indexing a column named city, the index value of city is the row key. The column names are the keys of the records. To see a detailed example, please refer to wikipedia.

- - ### Field Summary

    - ### Fields inherited from class org.apache.cassandra.db.index.AbstractSimplePerColumnSecondaryIndex

      `columnDef, indexCfs`

    - ### Fields inherited from class org.apache.cassandra.db.index.SecondaryIndex

      `baseCfs, columnDefs, CUSTOM_INDEX_OPTION_NAME, keyComparator, logger`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `KeysIndex()`

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `SecondaryIndexSearcher` | `createSecondaryIndexSearcher(java.util.Set<java.nio.ByteBuffer> columns)` Called at query time Creates a implementation specific searcher instance for this index type
    `protected AbstractType` | `getExpressionComparator()`
    `protected java.nio.ByteBuffer` | `getIndexedValue(java.nio.ByteBuffer rowKey, Cell cell)`
    `boolean` | `indexes(CellName name)` Returns true if the provided cell name is indexed by this secondary index.
    `boolean` | `isIndexEntryStale(java.nio.ByteBuffer indexedValue, ColumnFamily data, long now)`
    `protected CellName` | `makeIndexColumnName(java.nio.ByteBuffer rowKey, Cell cell)`
    `void` | `validateOptions()` Validates the index_options passed in the ColumnDef

    - ### Methods inherited from class org.apache.cassandra.db.index.AbstractSimplePerColumnSecondaryIndex

      `delete, estimateResultRows, expressionString, forceBlockingFlush, getIndexCfs, getIndexKeyComparator, getIndexKeyFor, getIndexName, init, insert, invalidate, reload, removeIndex, truncateBlocking, update`

    - ### Methods inherited from class org.apache.cassandra.db.index.PerColumnSecondaryIndex

      `getNameForSystemKeyspace, validate`

    - ### Methods inherited from class org.apache.cassandra.db.index.SecondaryIndex

      `buildIndexAsync, buildIndexBlocking, createInstance, getBaseCfs, getColumnDefs, getIndexComparator, isIndexBuilt, setIndexBuilt, setIndexRemoved`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### KeysIndex

          public KeysIndex()

  - ### Method Detail

    - #### getIndexedValue

          protected java.nio.ByteBuffer getIndexedValue(java.nio.ByteBuffer rowKey,
                                            Cell cell)

      Specified by:
        `getIndexedValue` in class `AbstractSimplePerColumnSecondaryIndex`

    - #### makeIndexColumnName

          protected CellName makeIndexColumnName(java.nio.ByteBuffer rowKey,
                                     Cell cell)

      Specified by:
        `makeIndexColumnName` in class `AbstractSimplePerColumnSecondaryIndex`

    - #### createSecondaryIndexSearcher

          public SecondaryIndexSearcher createSecondaryIndexSearcher(java.util.Set<java.nio.ByteBuffer> columns)

      Description copied from class: `SecondaryIndex`
      Called at query time Creates a implementation specific searcher instance for this index type
      Specified by:
        `createSecondaryIndexSearcher` in class `SecondaryIndex`
      Parameters:
        `columns` - the list of columns which belong to this index type
      Returns:
        the secondary index search impl

    - #### isIndexEntryStale

          public boolean isIndexEntryStale(java.nio.ByteBuffer indexedValue,
                                  ColumnFamily data,
                                  long now)

    - #### validateOptions

          public void validateOptions()
                               throws ConfigurationException

      Description copied from class: `SecondaryIndex`
      Validates the index_options passed in the ColumnDef
      Specified by:
        `validateOptions` in class `SecondaryIndex`
      Throws:
        `ConfigurationException`

    - #### indexes

          public boolean indexes(CellName name)

      Description copied from class: `SecondaryIndex`
      Returns true if the provided cell name is indexed by this secondary index.
      Specified by:
        `indexes` in class `SecondaryIndex`

    - #### getExpressionComparator

          protected AbstractType getExpressionComparator()

      Specified by:
        `getExpressionComparator` in class `AbstractSimplePerColumnSecondaryIndex`

Copyright © 2014 The Apache Software Foundation