Class CollectionKeyIndexBase

  • All Implemented Interfaces:
    Index
    Direct Known Subclasses:
    CollectionEntryIndex, CollectionKeyIndex

    public abstract class CollectionKeyIndexBase
    extends CassandraIndex
    Common superclass for indexes that capture collection keys, including indexes on such keys themselves. A cell indexed by this index will have the general form: ck_0 ... ck_n c_name [col_elt] : v where ck_i are the cluster keys, c_name the CQL3 column name, col_elt the collection element that we want to index (which may or may not be there depending on whether c_name is the collection we're indexing), and v the cell value. Such a cell is indexed if c_name is the indexed collection (in which case we are guaranteed to have col_elt). The index entry can be viewed in the following way: - the row key is determined by subclasses of this type. - the cell name will be 'rk ck_0 ... ck_n' where rk is the row key of the initial cell.
    • Method Detail

      • buildIndexClusteringPrefix

        public <T> CBuilder buildIndexClusteringPrefix​(java.nio.ByteBuffer partitionKey,
                                                       ClusteringPrefix<T> prefix,
                                                       CellPath path)
        Description copied from class: CassandraIndex
        Used to construct an the clustering for an entry in the index table based on values from the base data. The clustering columns in the index table encode the values required to retrieve the correct data from the base table and varies depending on the kind of the indexed column. See indexCfsMetadata for more details Used whenever a row in the index table is written or deleted.
        Specified by:
        buildIndexClusteringPrefix in class CassandraIndex
        Parameters:
        partitionKey - from the base data being indexed
        prefix - from the base data being indexed
        path - from the base data being indexed
        Returns:
        a clustering prefix to be used to insert into the index table
      • decodeEntry

        public IndexEntry decodeEntry​(DecoratedKey indexedValue,
                                      Row indexEntry)
        Description copied from class: CassandraIndex
        Used at search time to convert a row in the index table into a simple struct containing the values required to retrieve the corresponding row from the base table.
        Specified by:
        decodeEntry in class CassandraIndex
        Parameters:
        indexedValue - the partition key of the indexed table (i.e. the value that was indexed)
        indexEntry - a row from the index table
        Returns: