Tuesday, December 25, 2012

PTI - Chapter 10

I.     True/False

    1.   T

    2.   T

    3.   F

    4.   T

    5.   F

    6.   F

    7.   T

    8.   T

    9.   F

    10. T

II.     Multiple Choices

    1. B

    2. A

    3. D

    4. B

    5. A

    6. B

    7. B

    8. A

III.     Matching

    1.  E

    2.  G

    3.  C

    4.  B

    5.  J

    6.  A

    7.   I

    8.  D

    9.  H

    10. F

IV.     Short Answer

1.   Validation is the process of comparing data with a set of rules or values to find out if the data is correct.

Five types of validity checks: Alphabetic checks, Numeric checks, Range checks, Consistency checks, Completeness checks.

2.    In data redundancy each department or area in an organization has its own files in a file processing system, by duplicating data it wastes resources such as storage space and people’s time, also data redundancy can increase the chance of error.

Isolated data often it’s difficult to access data stored in separate files in different department. Sharing data from multiple, separate files to generate such a list in a file processing system often is a complicated procedure and usually requires the experience of a computer programmer.

3.   When an organization uses a database approach, many programs and users share the data in the database.

Five strengths of the database approach:

·         Reduces Data Redundancy, most data items are stored in only one file, which greatly reduces duplicated data.

·         Improved data Integrity, when users modify data in the database, they make change to one file instead of multiple files.

·         Shared data, The data in a database environment belongs to and is shared, usually over a network, by the entire organization.

·         Easier Access, the database approach allows nontechnical users to access and maintain data, providing they have the necessary privileges.

·         Reduces Development Time, it often is easier and faster to develop programs that use the database approach.

4.   How to use a Simple Query Wizard:

·         Select the fields from the Available Fields list you want to be displayed in the resulting query.

·         Assign a name to the query, so that you can open it later.

·         View the query result on the screen.

Query by example is a feature that has a graphical user interface to assist users with retrieving data.

5.   Advantages of object-oriented database:

They can store more type of data, access this data faster, and allow programmers to reuse object.

Four examples of object-oriented database:

·         A multimedia database stores images, audio clips, and/or video clips, for example, a GIS database stores maps and other geographic data.

·         A groupware database stores documents such as schedules, calendars, manuals, memos, and reports.

·         A computer-aided design database stores data about engineering, architectural, and scientific design.

·         A hypertext database contains text links to other types of documents. A hypermedia database contains test, graphic, video, and sound.

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