FUNDAMENTALS OF DATABASE SYSTEMS Fourth Edition phần 7 ppsx

... available systems included GEMSTONE/OPAL of GemStone Systems, ONTOS of Ontos, Objectivity of Objectivity Inc., Versant of Versant Object Technology, ObjectStore of Object Design, ARDENT of ARDENT Software," and POET of POET Software. These represent ... since the majority of 00 databases support types, we will assume that extents are collections of objects of the...

Ngày tải lên: 08/08/2014, 18:22

... units of database processing. Transaction processing systems are systems with large databases and hundreds of concurrent users that are executing database transactions. Examples of such systems ... any effects of the transaction on the database. The preservation of consistency is generally considered to be the responsibility of the programmers who write the databas...

Ngày tải lên: 08/08/2014, 18:22

... case we can consider the domain of OLOCATIONS to be the power set of the set of single locations; that is, the domain is made up of all possible subsets of the set of single locations. 296 IChapter ... dependencies in the left-hand side of the inference rule but does not satisfy the dependencies in the right-hand side. a. {W -7 Y, X -7 Z} F {WX -7 Y} b. {X -7 Y} and Y :2...

Ngày tải lên: 08/08/2014, 18:22

... discussing the role of information systems in organizations; database systems are looked upon as a part of information systems in large-scale applica- tions. We discussed how databases fit within an ... Discuss the importance of Requirements Collection and Analysis. 12.6. Consider an actual application of a database system of interest. Define the requirements of the diff...

Ngày tải lên: 08/08/2014, 18:22

... 2003-06-01 now Wong 333445555 25000 4 9998 877 77 1999-08-20 2001-01-31 Wong 333445555 30000 5 9998 877 77 2001-02-01 2002-03-31 Wong 333445555 40000 5 888665555 2002-04-01 now Brown 2224 477 77 28000 4 9998 877 77 2001-05-01 2002-08-10 Narayan 666884444 38000 ... in a database. Because part of the theoretical foundation for some deductive database systems is mathematical logic, s...

Ngày tải lên: 08/08/2014, 18:22