Discovering Computer 2011 – Living in a Digital World
Lecturer : Tri Djoko Wahjono
- Data is a collection of unprocessed items, which can include text, numbers, images, audio, and video. (True)
- A database management system allows users to create forms and reports from the data in the database. (True)
- A range check ensures users enter only numeric data in a field. (False)
- A check digit often confirms the accuracy of a primary key value. (True)
- Databases require less memory, storage, and processing power than a file processing system. (False)
- A report is a window on the screen that provides areas for entering or modifying data in a database. (False)
- Continuous backup is a backup plan in which all data is backed up whenever a change is made. (True)
- A relationship is a link within the data in a database. (True)
- Normalization is a process designed to ensure the data within the relations (tables) is duplicated so that it is not lost. (False)
- The data in a distributed database exists in many separate locations throughout a network or the Internet. (True)
- B. Timely
- A. Composite key
- D. File maintenance
- B. Determines whether a number is within a specified range
- A. Less complexity
- B. Data dictionary
- B. Principle of least privilege
- A. Decides on the proper placement of field
- Field name, e. uniquely identifies each field
- Field size, g. defines the maximum number of characters a field can contain
- Data type, c. specifies the kind of data a field can contain and how the field is used
- Primary key, b. field that uniquely identifies each record in a file
- Query language, j. consists of simple, English-like statements that allow users to specify the data to display, print, or store
- Log, a. listing of activities that modify the contents of a database
- Recovery utility, i. uses the logs and/or backups to restore a database when it becomes
damaged or destroyed
- GIS, d. database that stores maps and other geographic data
- Data modeler, h. person who focuses on the meaning and usage of data
- Database administrator, f. creates and maintains the data dictionary, manages security of the database, monitors the performance of the database, and checks backup and recovery procedures
- – What is validation?
Validation is the process of comparing data with a set of rules or values to find out if the data is correct.
– What are five types of validity checks?
Five types of validity checks are alphabetic checks, numeric checks, range checks, consistency checks, and completeness checks.
- – Why is data redundancy a weakness of file processing systems?
Data redundancy a weakness of file processing systems because data redundancy means same information is duplicated in several files. This makes data redundancy.
– Why is isolated data a weakness of file processing systems?
Isolated data a weakness of file processing systems because data are scattered in various files, and the files may be in different format, writing new application program to retrieve data is difficult
- – What is the database approach?
Database approach is a approach whereby a pool of related data is shared by multiple application programs; offers significant advantages over traditional file-based approach
– Describe five strengths of the database approach.
Reduced Data Redundancy — Most data items are stored in only one file, which greatly reduces duplicate data. Improved Data Integrity — When users modify data in the database, they make changes 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. Reduced Development Time — It often is easier and faster to develop programs that use the database approach.
- – Describe how you might use a Simple Query Wizard.
I might use a Simple Query Wizard for a query that searches for and lists students in an unversity.
– What is query by example?
Query by Example (QBE) is a database query language that has a graphical user interface to assist users with retrieving data.
- – What are the advantages of object-oriented databases?
Object-oriented databases have several advantages : they can store more types of data, access this data faster, and allow programmers to reuse objects.
– Describe four examples of object-oriented databases.
A multimedia database stores images, audio clips, and/or video clips. A groupware database stores documents such as schedules, calendars, manuals, memos, and reports. A computer-aided design (CAD) database stores data about engineering, architectural, and scientific designs. A hypertext database contains text links to other types of documents.