CHAPTER 7 STORING ORGANIZATIONAL INFORMATION-DATABASE
Relational
database fundamentals.
Database- maintains information about various types
of object(inventory), events(transactions), people(employees), and
place(ware-house).
Hierarchical database model- information organized into
tree-like structure that allows repeating information using parent/child
relationships in such a way that it cannot have too many relationships.
Network database model - Is
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.
Entity – person, place, thing, transaction, or
event about which information is stored.
Attributes – fields or columns are characteristics or
properties of an entity class.
Keys
and Relationships.
Primary key- is a field that uniquely
identifies a given entity in a table.
Foreign key- in the relational database
model is primary key of one table that appears between as an attribute in another
table and acts to provide logical relationship between the two tables.
Relational database adv advantages.
- increased flexibility
logical view- information focus on how users logically access information to meet their particular business needs.
- increased scalability and performance
performance- measures on how quickly a system performs a certain process or transaction.
- reduced information redundancy
- increased information integrity
integrity constraints- rules that help ensure the quality information.
- rational integrity constraints
- business-critical integrity constraints
business-critical integrity constraints- enforce business rules vital to an organization's success and often require more insight and knowledge than relational integrity constraints.
- increased information security
Database management systems.
database management systems(DBMS)- software through which usrs and application programs interact with a database.
Data-driven websites
" is an interactive website kept constantly update and relevant to the needs of its customers through the use of a database"
- data-driven website business advantages
- development
- content management
- future expandability
- minimizing human errors
- cutting production and update costs.
- more efficiently
- improved stability
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 systems and sends it automatically to all upstream systems ans processes.