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RELATIONAL DATABASE FUNDAMENTALS
- Information is everywhere in an organization
- Information is stored in databases
Ø Database – maintains information about various
types of objects (inventory), events (transactions), people (employees), and
places (warehouses)
- Database models include;
Ø Hierarchical database model – information is
organized into a tree-like structure (using parent/child relationships) in such
a way that it cannot have too many relationships.
ENTITIES AND ATTRIBUTES
- Entity – a person, place, thing, transaction, or
event about which information is stored
Ø
The rows in each table contains the entities
- Attributes (fields, columns) – characteristics or
properties of an entity class
Ø
The columns in each table contain the attributes
KEYS AND RELATIONSHIPS
- Primary keys and foreign keys identity the
various entity classes (tables) in the database
Ø
Primary key – a fields (or group of fields) that
uniquely identities a given entity in a table
Ø
Foreign key – a primary key of one table that
appears an attribute in another table and acts to provide a logical
relationships among the two tables
RELATIONAL DATABASE ADVANTAGES
- Database advantages from a business perspective
include;
Ø
Increased flexibility
Ø
Increased scalability and performance
Ø
Reduced information redundancy
Ø
Increased information integrity (quality)
Ø
Increased information security
INCREASED FLEXIBILITY
- A well-designed database should;
Ø
Handle changes quickly and easily
Ø
Provide users with different views
Ø
Have only one physical views
§
Physical view – deals with the physical storage
of information on a storage device
Ø
Have multiple logical views
§
Logical view – focuses on how users logically
access information
INCREASED SCALABILITY AND PERFORMANCE
- A database must scale to meet increased demand,
while maintaining acceptable performance levels
Ø
Scalability – refers to how well a system can
adapt to increased demands
Ø
Performance – measures how quickly a system
performs a certain process or transaction
REDUCED INFORMATION REDUNDANCY
- Databases reduce information redundancy
Ø
Redundancy – the duplication of information or
storing the same information in multiple places
- Inconsistency is one of the primary problems
with redundant information
INCREASED INFORMATION SECURITY
- Information is an organization asset and must be
protected
- Databases offer several security features
including;
Ø
Password – provides authentication of the user
Ø
Access level – determines who has access to the
different types of information
Ø
Access control – determines types of user
access, such as read-only access
DATABASE MANAGEMENT SYSTEMS
- Database management systems (DBMS) – software through
which users and application programs interact with a database
DATA-DRIVEN WEB SITES
- Data-driven Web sites – an interactive Web site
kept constantly updated and relevant to the needs of its customers through the
use of database
DATA-DRIVEN WEB SITE BUSINESS ADVANTAGES
- Development
- Content Management
- Future Expandability
- Minimizing Human Error
- Cutting Production and Update Costs
- More Efficient
- Improved Stability
DATA-DRIVEN BUSINESS INTELLIGENT
- BI in a data-driven Web site
INTEGRATING INFORMATION AMONG MULTIPLE DATABASES
- Integration – allows separate systems to
communicate directly with each other
Ø
Forward integration – takes information entered
into a given system and sends it automatically to all downstream systems
and processes
Ø Backward integration – takes information entered into a given system and sends it automatically to all upstream systems and processes
Question?
1.
Define the fundamental concepts of the
relational database model
2.
Evaluate the advantages of the relational
database model
3.
Compare relational integrity constraints and
business critical integrity constraint
4.
Describe the benefits of a data driven Web site
5.
Describe the two primary methods for integrating
information across multiple database
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