Accelerated query operators for high-speed, in-memory online analyctical processing queries and operations

摘要

An additional data structure can be initialized for a column of compressed data to include a prefix storing, for each block of values in the column, a total number of bits set in previous blocks in the bit vector. A block number can be determined for a target block of the plurality of blocks, for example by checking whether or not a specified row number is located in the prefix. If the specified row number is located in the prefix, the prefix value of the prefix is returned, the most frequently occurring value is returned if a corresponding bit in the bit vector in the specified row number is not located in the prefix, or a position of the specified row in an index vector for the column is returned.