Exam 9: Data Management Layer Design

A(n) _____ occurs when data are stored redundantly in a database and only some of the instances are updated when a change is needed.

There are several techniques that the project team can use to try to speed up access to the data: denormalization, clustering, and indexing.

The applicability of NOSQL data stores is limited and they are NOT applicable to traditional business transaction processing systems.

SQL operates on _____.

Look-up files store core information that is important to the business and to the application, and are usually kept for long periods of time with new records appended to the end of the file.

Explain the object persistence format type known as files.

When looking for a specific object of interest, on average 25% of a sequential access file will have to be searched in order to find that object.

Information systems consultants, Drew and Becky, have just visited the site of a potential customer. Video-Audio-Images Extra, Inc., is an old established organization that was one of the first companies to videotape weddings, high school musicals, and church presentations. Today they have transformed into a multinational company that performs audio and video recording and mixing, digital re-mastering, and computer graphics for feature films, MTV videos, commercials and video games. During the interview Becky learned that the company has a legacy database system that should soon be replaced. The new system should be able to handle only accounting, purchasing, human resources, and inventory control for the company. What object persistence format would you recommend to Becky and Drew? Support your answer.

When the analyst is evaluating a data model to ensure that all fields in a record depend fully on the entire primary key, the analyst is making sure that the data model conforms to the second normal form.

The object persistence format that supports simple data types only is OODBMS.

Mapping between the problem domain objects and an OODBMS is a straightforward one-to-one mapping.

Explain the term denormalization.

It is likely easier today to find expertise in OODBMS than in RDBMS.

A method for improving data access that involves physically arranging the records on the storage medium is called clustering.

A relational database may be optimized for _____.

The two primary dimensions to optimize a relational database are storage efficiency and future needs.

Update anomalies occur when some instances of redundantly stored data are overlooked when an update occurs.

A file contains an electronic list of information that is formatted for a particular transaction, and the information is changed and manipulated by programs that are written for those purposes.

Null values in a database are easy to interpret.

Data may be stored in the following formats _____.