Design Objectives Flashcards
What is RDBMS?
Relational database management system
Why should you use database creation tools after you’ve created a logical data database structure
The purpose of RDBMS programs is to help you in the implementation to save time and give time to create and build the end-user application
Why should you be concerned with database design?
Database design is crucial to the consistency, integrity, and accuracy of the data in the database
Why is database design important
Improper design will result in inaccurate information and difficulty to retrieve information
What are the three steps in database design?
First: describe the size, shape, unnecessary systems for the database. Address the informational & operational needs of the business. Implementation: use your RDBMS program. Create tables, set up table relationships, establish levels of data integrity. Application: create an application that allows the users to interact with the data stored in the database
What is a theory
A general proposition used as principles, because databases are based on set theory and first order predicate logic you are able to design databases that work every time
What causes many problems in databases
Redundant data, duplicate data, invalid data, absence of required data
Good design 1: the database supports both required an ad hoc information retrieval
Necessary data stored to support information requirements required during the design process plus any ad hoc queries that maybe posed by the user
Good design 2: tables are constructed properly and efficiently
Each table represents a single subject, relatively distinct fields, redundant data to a minimum, identified throughout the database By field with unique values
good design3: data integrity is imposed at the field, table and relationship levels
These levels of integrity health guarantee data structures and values will be valid and accurate at all times
Good design4: database supports business rules relevant to the organization
Database provides valid and accurate information meaningful to the business
Good design 5: database lens itself to future growth
Structure should be easy to modify or expand as the information requirements of the business change and grow
What are the benefits of good database design
Structure is easy to modify and maintain, data is easy to modify, information is easy to retrieve, and user applications are easy to develop and build
What are the three phases of traditional database design
1: requirements analysis
2: data modelling
3: normalization
What is the data modeling phase
Visually representing the information through entity relationship diagramming, semantic object modeling, object role modeling or UML modelling
