Exam 9: Database Design

Correct Answer:

Verified

Centralized design is productive when the data component is composed of a relatively small number of objects and procedures.The design can be carried out and represented in a fairly simple database.Centralized design is typical of relatively simple and/or small databases and can be successfully done by a single person (database administrator)or by a small,informal design team.The company operations and the scope of the problem are sufficiently limited to allow even a single designer to define the problem(s),create the conceptual design,verify the conceptual design with the user views,define system processes and data constraints to ensure the efficacy of the design,and ensure that the design will comply with all the requirements.(Although centralized design is typical for small companies,do not make the mistake of assuming that centralized design is limited to small companies.Even large companies can operate within a relatively simple database environment.)Decentralized design might be used when the data component of the system has a considerable number of entities and complex relations on which very complex operations are performed.Decentralized design is also likely to be employed when the problem itself is spread across several operational sites and each element is a subset of the entire data set.In large and complex projects,the database design typically cannot be done by only one person.Instead,a carefully selected team of database designers is employed to tackle a complex database project.Within the decentralized design framework,the database design task is divided into several modules.Once the design criteria have been established,the lead designer assigns design subsets or modules to design groups within the team.

Correct Answer:

Verified

A full backup of the database,or dump of the entire database.In this case,all database objects are backed up in their entirety.
A differential backup of the database,in which only the last modifications to the database (when compared with a previous full backup copy)are copied.In this case,only the objects that have been updated since the last full backup are backed up.
A transaction log backup,which backs up only the transaction log operations that are not reflected in a previous backup copy of the database.In this case,only the transaction log is backed up; no other database objects are backed up.