RELATIONAL DATABASE FUNDAMENTALS
- Information is everywhere in an organization
- Information is stored in databases
Database – maintains information about various types of objects (inventory), events (transactions), people (employees), and places (warehouses)]
Database models are:
- 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.
- Entity – a person, place, thing, transaction, or event about which information is stored
The rows in each table contains the entities
- Attributes (fields, columns) – characteristics or properties of an entity class
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
Primary key – a fields (or group of fields) that uniquely identities a given entity in a table
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;
Increased flexibility
Increased scalability and performance
Reduced information redundancy
Increased information integrity (quality)
Increased information security
INCREASED FLEXIBILITY
- A well-designed database should;
Handle changes quickly and easily
Provide users with different views
Have only one physical views
§ Physical view – deals with the physical storage of information on a storage device
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
Scalability – refers to how well a system can adapt to increased demands
Performance – measures how quickly a system performs a certain process or transaction
REDUCED INFORMATION REDUNDANCY
- Databases reduce information redundancy
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;
Password – provides authentication of the user
Access level – determines who has access to the different types of information
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
Forward integration – takes information entered into a given system and sends it automatically to all downstream systems and processes
Backward integration – takes information entered into a given system and sends it automatically to all upstream systems and processes
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