Databases Reference
In-Depth Information
12
Component Database Systems
Andreas Geppert and Klaus R. Dittrich
12.1
Introduction
DBMSs support individual applications and comprehensive information sys-
tems with modeling and long-term reliable storage capabilities of data as well
as with retrieval and manipulation facilities for persistent data by multiple,
concurrent users or transactions. SQL [1], the transaction abstraction [2],
and the concept of a data modelmost notably the relational model [3] and,
to a lesser extent, the object-oriented data models [4, 5]are crucial ingredi-
ents of data management. DBMSs are well established and form the corner-
stones of virtually every enterprise: IS.
Traditionally, data elements stored in DBs were simply structured, for
example, employee records and product and stock information. Transactions
typically were of short duration and often needed to access only a few data
items. Queries were usually simple, and techniques to efficiently answer
them well understood. Taking a broader view, DBMS-based information
systems have usually been built in a rather DB-centric way, that is, environ-
ment decisions like the use of mainframe-based or client/server architectures
are typically based on what the DBMS itself requires or supports in that
respect.
Recently, however, more and more new and demanding application
domains have emerged that also want to benefit from DB technology, and
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