Fundamentals of database systems 6ed

... while the database is operational and does not require recompilation of the database schema. Certain checks must be done by the DBMS to ensure that the changes do not affect the rest of the database ... TABLE command. For example, if we no longer wish to keep track of dependents of employees in the COMPANY database of Figure 4.1, we can get rid of the DEPENDENT relation...

Ngày tải lên: 07/12/2013, 11:33

. think of for this database? 3.15. Consider the following relations for a database that keeps track of business trips of salespersons in a sales office: SALESPERSON(Ssn,. database. Examples of such constraints are the salary of an employee should not exceed the salary of the employee’s supervisor and the maximum number of

Ngày tải lên: 20/02/2014, 05:21

... think of a word database you should generally think of any type of data stored inside a computer − even a SomeFile.pas file (code to some Delphi unit) is some kind of database. Another type of database ... see some of the concepts of database design and try to build a simple database. Before we start interacting with databases using Delphi, it is a good idea to get a fe...

Ngày tải lên: 16/04/2014, 11:14

... current systems have a variety of special case code to perform logical logging of events rather than physical logging of the changes of bits. There are at least two reasons 12 for this method of logging. ... involving a single relation can be processed with a scan of the relation, a scan of a portion of the primary index, or a scan of a portion of one secondary index. Jo...

Ngày tải lên: 22/10/2013, 10:15

... range of a linear transformation L of U into V is the set of vectors v of V into which some vector u of U is mapped, i.e., the range of L is defined as the set of v = Lu, for every vector u of U.Thekernel ... position and orientation of the vehicle body. As a matter of fact, the control of rolling robots bears common features with that of the redundancy resolution of...

Ngày tải lên: 19/01/2014, 18:20

... the scope of our subject, we have to establish the genealogy of robotic mechanical systems. These are, obviously, a subclass of the much broader class of mechanical systems. Mechanical systems, ... Dynamics of Complex Robotic Mechanical Systems 401 10.1Introduction 401 10.2 Classification of Robotic Mechanical Systems with Regard toDynamics 402 10.3 The Structure of the Dy...

Ngày tải lên: 19/01/2014, 18:20

... deducible, in the presence of OVERLAPS + and INSIDE + , by using Rules I, II, and III. Proof. The reader may refer to the proof of Claim 3.2 in Appendix of [23] for the proof of Claim 3.9. Therefore, ... spatial relationship “A is left of B” (written as “A left -of B”) in [8] means that the position of the centroid of A is left of that of B (and we say “A left -of B” is re...

Ngày tải lên: 07/03/2014, 14:20

... orientation in database systems, which is applied to characterize the engineering database systems investigated in the remainder of this section. 3.1 The (Pure) Relational Database Systems In ... language aspects of CAD systems, we analyze several recent proposals for object-oriented database systems with respect to geometric modeling, all of which evolved out of th...

Ngày tải lên: 07/03/2014, 23:20