Name the main steps in database design what is the goal of each step? Which step is the er model is mainly used in?
Answers
Answer:
Determine the purpose of your database. ...
Find and organize the information required. ...
Divide the information into tables. ...
Turn information items into columns. ...
Specify primary keys. ...
Set up the table relationships. ...
Refine your design. ...
Apply the normalization rules.
Answer:
The database design can be divided into 6 steps.ER model is
relevent to first 3 steps
1.Requirement analysis
2.Conceptual databasedesign
3.Logical database design
4.Schema refinement
5.Physical database design:.Ex:Indexes
6.Application and security design
Explanation:
Conceptual design: (ER Model is used at this stage.)
– A database `schema’ in the ER Model can be
represented pictorially (ER diagrams).
– Can map an ER diagram into a relational schema
ER Model Basics
• Entity: Real-world object distinguishable from other
objects. An entity is described (in DB) using a set of
attributes.
• Entity Set: A collection of similar entities. E.g., all
employees.
– All entities in an entity set have the same set of
attributes.
– Each entity set has a key.(minimal set of
attributes whose values uniquely identify entity
in set)
– Each attribute has a domain.