
Distributed database systems
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The users of a database are often widely dispersed, for example, throughout a building,
a city, nationally or internationally. They typically belong to departments or divisions
located at geographically distinct sites. Such a physical organisation necessitates the
linking of sites by a communications network if the users are to access a shared
database. However, transmission speeds across a network are much slower than for
local access to a database, and the extent and complexity of the network make it more
vulnerable to failure. These disadvantages may be alleviated by distributing the
database amongst ...