- Database - maintains information about various types of objects (inventory), events (transactions), people (employees), and places (warehouses).
- Hierarchical database model - information is organized into a tree-like structure in such a way that it cannot have too many relationships.
- Network database model - a flexible way of representing objects and their relationships.
- Relational database model - stores information in the form of logically related two-dimensional tables.
Entities and Attributes :
=> A person, place, thing, transaction or event about which information is stored.
=> Characteristics or properties of an entity class.
Keys and Relationships :
- Primary key - a field (or group of fields) that uniquely identifies 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 relationship among the two tables.
Relational Database Advantages :
- Increased flexibility.
Physical view - deals with the physical storage of information on a storage device.
Logical view - focuses on how users logically access information.
- Increased scalability and performance.
Performance - measures how quickly a systems performs a certain process or transaction.
- Reduced information redundancy.
- Increase information integrity ( quality ).
Integrity constraint - rules that help ensure the quality of information.
- Increased information security.
Access level - determines who has access to the different types of information.
Access control - determines types of user access, such as read-only access.
Data-Driven Website Business Advantages :
- Content management.
- Future expandability.
- Minimizing human error.
- Cutting production and update costs.
- More efficient.
- Improved stability.
Integrating Information among Multiple Databases :
- Integration - allows separate systems to communicate directly with each other.
- Forward integration - takes information entered into a given systems 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.