Exam 1-Chapter 1

Question 1

Data

Answer 1

Raw facts and the building blocks of information

Question 2

Information

Answer 2

the result of processing raw data to reveal meaning; produced by processing data; used to reveal meaning in data

Question 3

Knowledge

Answer 3

Data are the foundation of information, which is the bedrock of knowledge

Question 4

Metadata

Answer 4

Data about data; provides description of data characteristics and relationships in data; complements and expands value of data

Question 5

Database Management System (DBMS)

Answer 5

Manages structure and controls access to data; intermediary between the user and the database; enables data to be shared; integrates many users’ views of the data

Question 6

Advantages of a DBMS

Answer 6

Improved data sharing; Improved data security; Better data integration; Minimized data inconsistency; Improved data access; Improved decision making; Increased end-user productivity

Question 7

Classifications of Databases

Answer 7

Number of users; Database locations; Expected type and extent of use

Question 8

Single-User Database

Answer 8

Supports only one user at a time (desktop database: single-user; runs on PC)

Question 9

Multiuser Database

Answer 9

Supports multiple users at the same time (workgroup and enterprise databases)

Question 10

Centralized Database

Answer 10

Data located at a single site

Question 11

Distributed Database

Answer 11

Data distributed across several different sites

Question 12

Operational Database

Answer 12

Supports a company’s day-to-day operations (transactional or production database)

Question 13

Data Warehouse

Answer 13

Stores data used for tactical or strategic decisions

Question 14

Database Design

Answer 14

Focuses on design of database structure used for end-user data (designer must identify database’s expected use

Question 15

Well-Designed Database/Poorly Designed Database

Answer 15

Well-design: (facilitates data management; generates accurate and valuable information)
Poorly designed datatbase: (causes difficult-to-trace errors; may lead to bad decision making)

Question 16

Manual Systems

Answer 16

Served as a data repository for small data collections; cumbersome for large collections

Question 17

Data Processing (DP) Specialist

Answer 17

Computerized file system; converted computer file structure from manual system; wrote software that managed the data; designed the application programs

Question 18

Increaed Files

Answer 18

As number of files increased, file systems evolved; each file used its own applicaton program to store, retrieve, and modify data; each file was owned by individual or department that commissioned its creation

Question 19

Problems with File System Data Processing

Answer 19

File systems were an improvement over manual system (file systems used for more than two decades; understanding the shortcomings of file systems aids in development of modern databases; many problems not unique to file systems)
Even simple file system retrieval task required extensive programming (ad hoc queries impossible;changing existing structure difficult)
Security features difficult to program (often omitted in file system environment)

Question 20

Structural Dependence

Answer 20

Access to a file is dependent on its own structure (all file system programs must be modified to conform to a new file structure)

Question 21

Structureal Indedependence

Answer 21

Change file structure without affecting data access

Question 22

Data Dependence

Answer 22

Data access changes when data storage characteristics change (eg, changing a data type)

Question 23

Data Independence

Answer 23

Data storage characteristics do not affect data access

Question 24

Logical Data Format

Answer 24

How human views the data

Question 25

Physical Data Format

Answer 25

How computer must work with data

Question 26

Each Program Accessing a File System File Must Contain

Answer 26

Lines specifying opening of specific file type Record specification Field Definitions

Question 27

Data Redundancy

Answer 27

Same data stored unnecessarily in different places (Having multiple copies of data=vulnerable to security breaches; Data stored in different locations is unlikely to be updated consistently)

Question 28

Data Inconsistancy

Answer 28

Different and conflicting versions of same data occur at different places

Question 29

Data Anomalies

Answer 29

Abnormalities when all changes in redundant data are not made correctly (update anomalies; insertion anomalies: cannot insert a fact about one entity without a fact about another entity; deletion anomaliies: if the customers are deleted we also lose the associated agent data)

Question 30

Database Systems

Answer 30

Database systems consists of logically related data stored in a single locical data repository (may be physically distributed among multiple storage facilities; DBMS eliminates most of file system's problems; current generation stores data structures, relationships between structures, and access paths) Defines and regulates the collection, storage, management, and use of data

Question 31

Database System Environment

Answer 31

Five major parts of a database system: - Hardware - Software - People - Procedures - Data

Question 32

Hardware

Answer 32

All the system's physical devices

Question 33

Software

Answer 33

Three types of software required: - Operating system software - DBMS software - Application programs and utility software

Question 34

People

Answer 34

All users of the database system (system and database administrators; database designers; systems analysts and programmers; end users)

Question 35

Procedures

Answer 35

Instructions and rules that goven the design and use of the database system

Question 36

Data

Answer 36

The collection of facts stored in the database

Question 37

Data Dictionary Management

Answer 37

DBMS stores definitions of data elements and relationships (metadate in a data dictionary DBMS looks up required data component structures and relationships Changes automatically recorded in the dictionary Do not have to modify all programs using the data and removes structural and data dependency

Question 38

Data Storage Management

Answer 38

DBMS creates and manages complex structures required for data storage Also stores related data entry forms, screen definitions, report definitions, etc

Question 39

Performance Tuning

Answer 39

Actiivities that make the database perform more efficiently

Question 40

Data Transformation and Presentation

Answer 40

DBMS transforms data entered to conform to required data structures DBMS transforms physically retrieved data to conform to user's logical expectations

Question 41

Security Management

Answer 41

DBMS creates a security system that enforces user security and data privacy Security rules determine which users can access the database, which items can be accessed, etc.

Question 42

Multiuser Access Control

Answer 42

DBMS uses sophisticated algorithms to ensure concurrent access does not affect integrity

Question 43

Backup and Recovery Management

Answer 43

DBMS provides backup and data recovery to ensure data safety and integrity Recovery management deals with recovery of database after a failure (critical to preserving database's integrity

Question 44

Data Integrity Management

Answer 44

DBMS promotes and enforces integrity rules (minizes redundancy; maximizes consistency) Data relationships stored in data dictionary used to enforce data integrity Integrity is especially important in transaction-oriented database systems

Question 45

Query Language

Answer 45

Nonprocedural language

Question 46

Structured Query Language (SQL)

Answer 46

The de facto query language (standard supported by majority of DBMS vendors

Question 47

Disadvantages of Database Systems

Answer 47

Increased costs: hardware, software, personal Management complexity: DB interfaces with many other technologies; security must also be constantly assessed Maintaining currency: software patches, security updates, personnel training Vendor dependence Frequent update/replacement cycles