EIS 3306 Chapter 1 Questions

What is the definition of a record?

A collection of related (logically connected) fields.

What is data redundancy?

A condition in which a data environment contains redundant (unnecessarily duplicated) data.

What is data independence?

A condition in which data access is unaffected by changes in the physical data storage characteristics.

What is structural independence?

A data characteristic in which changes in the database schema do not affect data access.

What is the definition of a file?

A named collection of related records.

What is the definition of a field?

An alphabetic or numeric character or group of characters that defines a characteristic of a person, place, or thing. For example, a person's Social Security number, address, phone number, and bank balance all constitute fields.

Why is data independence lacking in file systems?

Any program that accesses a file system's file must tell the computer not only what to do, but how to do it. Consequently, each program must contain lines that specify the opening of a specific type of file, its record specification, and its field definitions. Data dependence makes the file system extremely cumbersome from the point of view of a programmer and database manager.

What is the definition of data?

Raw facts, or facts that have not yet been processed to reveal their meaning to the end user

What is a DBMS?

The collection of programs that manages the database structure and controls access to the data stored in the database.

Which characteristics of the file system can data redundancy lead to?

The use of spreadsheets and tables in different parts of the organization can cause it.

What are the potential costs of implementing a database system?

They require sophisticated hardware, software, and highly skilled personnel. The cost of maintaining these can be substantial. Training, licensing, and regulation compliance are also expensive.

Which type is more prevalent in a typical business environment, unstructured or structured data?

Unstructured data are data that exist in their original raw state-- that is the format in which they are collected (ex. 37890). Structured data are the result of formatting unstructured data to facilitate storage, use, and the generation of information (ex. taking that number and storing it as text or as numeric). Most data you encounter are semi-structured.

List and describe the different types of databases.

a. number of users supported (single-user, desktop, multiuser, workgroup, enterprise ) b. where the data is located (centralized or distributed) c. type of data (general-purpose or discipline-specific) d. intended use of the data (operational or analytical) e. degree of structure (unstructured, structured, semi-structured)

What are the functions of a DBMS?

1. data dictionary management 2. data storage management 3. data transformation and presentation 4. security management 5. multiuser access control 6. back-up and recovery management 7. data integrity management 8. database access languages and application programming interfaces 9. database communication interfaces

What are the main components of a database system?

1. hardware 2. software 3. people 4. procedures 5. data

What are the advantages of a DBMS?

1. improved data sharing 2. improved data security 3. better data integration- "the big picture" 4. minimized data inconsistencies 5. improved data access- quick answers to ad hoc queries 6. improved decision-making and data quality 7. increased end-user productivity

What are the disadvantages of a DBMS?

1. increased cost 2. management complexity 3. maintaining currency 4. vendor dependence 5. frequent upgrades and replacement cycles

What are metadata?

Data about data; that is, data about data characteristics and relationships.

Explain the differences among data, information, and a database.

Data are raw facts that have not been processed. Information is data that has been processed and given context. Databases help to facilitate the manipulation of data to create information by providing an organizational structure that makes relationships and connections between data explicit.

Why is structural independence important?

It matters because if it doesn't exist (or is structural dependent) any change to a file's structure (i.e. adding a new field) would require a program to (1) read a record from the original file (2) transform the original data to conform to the new structure's storage requirements (3) write the transformed data into the new file structure and (4) repeat the steps for EVERY single record in the file.

What common problems does a collection of spreadsheets created by end users share with the typical file system?

- lengthy development time - difficulty of getting quick answers - complex system administration - lack of security - limited data sharing - extensive programming to make changes - creates data inconsistencies, redundancies, and anomalies