A data representation and retrieval method and apparatus enables to
quickly locate and extract specified data from a data file with use of
supplemental data stored in a small storage file. The method includes the
steps of providing a primary data file which stores a large volume of
recorded data where a location of each piece of recorded data is
represented by an offset value, providing a secondary data file which
stores supplemental data for assisting to search and retrieve the
recorded data from the primary data file, accessing the secondary data
file to retrieve supplemental data corresponding to search data specified
by a user, and accessing the primary data file at locations specified by
offset values derived from the supplemental data and retrieving the
recorded data therefrom.