Data vs Information
Data
- raw facts, or facts that have not yet been processed to reveal their meaning to the end
user.
Information
- result of processing raw data to reveal its meaning.
Knowledge
- implies familiarity, awareness, and understanding of information as it applies to an
environment.
Introducing the Database
Database
- A shared, integrated computer structure that houses a collection of related data.
- Contains two types of data: end-user(raw facts) and metadata.
Metadata
- Data about data
- This is where end-user data is integrated and managed
Database Management System (DBMS)
- Collection of programs that manages the database structure and controls access to the
data stored in the database
Data management
- The process that focuses on data collection, storage, and retrieval
- Common data management functions include: addition, modification, and listing
Roles and Advantages of the DBMS
1. Improved data sharing
2. Improved data security
3. Better data integration
4. Minimized data inconsistency
5. Improved data access
6. Improved decision making
7. Increased end-user productivity
Database Classifications
● Number of users supported
● Data Location
● Type of data stored
● Intended data usage
● Degree of data structured
Types of Database
Classification by Number of users
a. Single-user database: a database that supports only one user at a time
b. Multi User database: a database that supports multiple concurrent users
Types of Database Definition No. of Users
1. Desktop Database - Runs on a personal computer single
2. Workgroup - Usually supports fewer than 50 multiple
Database users
- Used for specific departments in
an organization
3. Enterprise Database - Overall company data multiple
representation that provides
support for present and future
needs
Classification by Data Location
Types of Database Definition Location
1. Centralized Database - Supports data located at a single centralized
site
2. Distributed Database - Supports data distributed across decentralized
several different sites
3. Cloud Database - Created and maintained using
cloud data services such as:
Microsoft Azure or Amazon AWS
Classification by Data Type
Types of Database Definition
1. General-purpose Database - Contains a wide variety of data used
in multiple disciplines
2. Discipline-specific Databases - Contains data focused on specific
subject areas
3. Operational Database - Designed to support a company’s
day-to-day operations
Analytical database
- Stores historical data and business metrics used exclusively for tactical or strategic
decision making
Types of Database Definition
1. Data warehouse - Stores data in a format optimized for
decision support
2. Online analytical processing (OLAP) - Tools for retrieving, processing, and
modeling data from the data
warehouse
3. Business intelligence - Captures and processes business
data to generate information that
supports decision making
Evolution of File System Data Processing
Manual FIle Systems
- Accomplished through a system of file folders and filing cabinets
Computerized File Systems
- Data processing (DP) specialist created a computer-based system to track data and
produce required reports
File System Redux
- Includes spreadsheet programs such as Microsoft Excel
Basic File Terminology
Field
- Character or group of characters that has a specific meaning
- Used to define and stores data
Record
- Logically connected set of one or more fields that describes a person, place, or thing
File
- Collection of related records
- Ex. a file might contain data about the students currently enrolled at Gigantic University
Problems with File System Data Processing
1. Lengthy development times
2. Difficulty of getting quick answers
3. Complex system administration
4. Lack of security and limited data sharing
5. Extensive programming
Structural and Data Dependence
Structural dependence
- Access to a file is dependent on its own structure
- All file system programs are modified to conform to a new file structure
Structural independence
- File structure is changed without affecting the application/s ability to access the data
Data Redundancy
- Unnecessarily storing the same data in different places
- Islands of information
- Increases the probability of having different versions of the same data
Results of uncontrolled data redundancy
- Poor data security
- Data inconsistency
- Data-entry errors
- Data integrity problems
Database Systems
Database Systems
- Consists of logically related data stored in a single logical data repository
Database Systems Environment
- Refers to an organization of components that define and regulate the collection, storage,
management, and use data within a database environment
The Five Components of Database System Environment
Hardware
- Refers to all the system’s physical devices
Software
- Three types of software:
a. Operation System (OS)
b. DBMS software
c. Application Program
People
- Component includes all users of the database systems
- Five types of users:
a. System Administrators
b. Database Administrators
c. Database Designers
d. System Analysts and Programmers
e. End-users
Procedures
- Instructions and rules that govern the design and use of the database system
Data
- Covers the collection of facts stored in the database
- Determining which data to enter into the database and how to organize that data is a
vital part of the database designer’s job
DBMS Functions
Data Dictionary Management
- Stores definitions of data elements and their relationships
Data Storage Management
- Performance tuning ensure efficient performance
Data Transformation and Presentation
- Data is formatted to conform to logical expectations
Security Management
- Enforces user security and data privacy
Disadvantages of Database Systems
1. Increased costs
2. Management complexity
3. Maintaining currency
4. Vendor dependence
5. Frequent upgrade/replacement cycles
