Object database management systems (ODBMS) were
initially designed to address several of the weaknesses
of RDBMS. These include the inability to store complete
objects directly in the database (both object state and
behavior: see Box 8.2 for an introduction to objects and
object technology). Because RDBMS were focused primarily
on business applications such as banking, human
resource management, and stock control and inventory,
they were never designed to deal with rich data types, such
as geographic objects, sound, and video. A further difficulty
is the poor performance of RDBMS for many types
of geographic query. These problems are compounded
by the difficulty of extending RDBMS to support geographic
data types and processing functions, which obviously
limits their adoption for geographic applications.
ODBMS can store objects persistently (semi-permanently
on disk or other media) and provide object-oriented query
tools. A number of commercial ODBMS have been developed
including GemStone/S Object Server from Gem-
Stone Systems Inc., Objectivity/DB from Objectivity Inc.,
ObjectStore from Progress Software, and Versant from
Versant Object Technology Corp.