Data, Information Systems and Databases

a. data - raw facts that differ from information in that they have not been processed for interpretation by the end user.

b. field - alpha or numeric characters or groups of characters used to define and store data.

c. record - A set of one or more fields used to connect all data associated with a specific subject, item, person, etc.

d. file - a collection of related records.

2. What is data redundancy, and which characteristics of the file system can lead to it?

Data redundancy occurs when the same pieces of data are stored in the different places unnecessarily. Redundancy can lead to both data inconsistency and data anomalies. Both can cause additional work as well as errors. Data redundancy is often the result of the file system's structure or lack of security. Structure of the file system controls where data is stored and if it is not designed efficiently, users are left with scattered redundant data.

3. Discuss the lack of data independence in file systems.

The lack of data independence contributes to inflexible, cumbersome file systems. Applications with data processed in the source code lack data independence and prevent other programs from being able to access data.

4. What is a DBMS, and what are its functions?

A DBMS (database management system) is software used to manage the structure, elements and data within a database. A DBMS is responsible for providing user-friendly access and controls between end user and database. Its main purpose is to improve functionality through improved data sharing, better data integration, minimized data inconsistency, improved data access, improved decision making, and increased end user productivity. This tool simplifies the management functions of complex databases.

5. What is data independence, and why is it important?

Data independence is an often desired trait of a file system. It allows changes to data to be made without any effect to the application programs attempting to access the data. This is important because of the benefits resulting from this trait. Programming is simpler and less error prone because code changes do not need to applied to each program accessing the data. It makes for a more efficient file system.

6. Explain the difference between data and information.

Data are the raw facts stored within the database that have yet to be processed for the end user. Information results from the processing of this raw data to produce meaning for interpretation by the end user.

7. Explain what data inconsistency is and why it occurs.

A database which is not designed with the right structure or functionality can result in varied versions of the same data. Data redundancy, a function of the design, can be a culprit for data inconsistency because scattered, duplicated data is often not updated in its entirety.

8. Discuss the different types of databases.

A single-user database will only support access or use by one user at a time. When used on one personal computer, it is known as a desktop.

Multiuser databases support use/access by multiple users at the same time and are divided into workgroup and enterprise databases. Workgroup databases are designated for smaller number of users, often 50 or less. Enterprise databases support large numbers of users in an organization, often more than 50.

Databases can also be classified based on location. Centralized databases store and manage data for a single site. A distributed database will manage and store data for several sites.

Finally, databases are often classified based on their function or type of manage information. For example, an operational database would be used to store and manage data in regards to the day to day operations of an organization. A data warehouse would contain data used to make strategic decisions. These databases often require extensive manipulation/processing of data.

9. What are the main components of a database system environment?

Hardware - physical devices associated with a database system.

Software - programs associated with the database system: the DBMS, OS (operating system), and application programs/utilities.

People - All of the database system (system administrators, database administrators, database designers, system analysts & programmers, and end users).

Procedures - these serve for the purpose of organization and instruction. They provide rules and guidelines for the design and use of the database system.

Data - refers to the raw facts that is entered and stored in the database. This is essential to generate the desired information.

10. What is metadata?

Data used to describe other data. This may describe how and when a set of data was collected or how the data is formatted.

11. Explain why database design is important.

Database design is a critical area for developing an effective database system. The intended use must be clearly understood to develop the most efficient design. This will help determine the type of database structure that is required. If thought and effort is not put into the design of a database, an organization may face many problems. Important data can be lost. Errors in decision making based on information retrieved from the database can cause significant harm to an organization. Ultimately, you may be relying on an unreliable system. Data and information are some of the most valuable assets to an organization and need a well designed database system.

12. Discuss the differences between transaction databases and data warehouse databases.

Transaction databases store and record data for the day to day operation of an organization. This may be used to track purchases, inventory and other critical operations.

Data warehouse databases focus on generating information from stored data with the intended purpose of being used in making strategic decisions. The structure is different from a transaction database so data can be manipulated and accessed quicker.