Browse Prior Art Database

Retrieval of Distributed Data

IP.com Disclosure Number: IPCOM000109605D
Original Publication Date: 1992-Sep-01
Included in the Prior Art Database: 2005-Mar-24
Document File: 1 page(s) / 56K

Publishing Venue

IBM

Related People

Krosner, SP: AUTHOR

Abstract

In a distributed data base system the data in the database may reside in several geographical locations. This article describes a mechanism to determine the most efficient place to retrieve a particular piece of data.

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This is the abbreviated version, containing approximately 80% of the total text.

Retrieval of Distributed Data

       In a distributed data base system the data in the
database may reside in several geographical locations.  This article
describes a mechanism to determine the most efficient place to
retrieve a particular piece of data.

      Efficiency in data retrieval can be measured in two dimensions.
The first dimension is the distance that the information must be
transmitted or the communications distance.  Communications expense
increases with distance as more repeaters are required to maintain
the signal integrity.

      The second dimension is the number of operations required to
materialize the actual piece of data from the database.  This
dimension is a function of the number of operations required (joins
and selects, etc.) to retrieve the actual data requested.  In a
relational database system, the same data value may be obtained via
several unique queries.

      Categorizing the efficiency of the data retrieval problem in
terms of the communications distance and the number of operations
required to materialize the data constrains the solution space to a
plane.

      Given that this is a two-dimensional problem space, we
construct a space-filling curve through the problem space, plot the
locations of the requesting location and the potential sources on the
plane and then apply the space-filling curve heuristic developed by
(*) to determine the shortest path between the requester and the
potential servers.  Since t...