Steps
in designing Star Schema
•
Identify a business process for analysis (like sales).
•
Identify measures or facts (sales dollar).
•
Identify dimensions for facts (product dimension, location dimension, time
dimension, organization dimension).
•
List the columns that describe each dimension. (region name, branch name, region
name).
•
Determine the lowest level of summary in a fact table (sales dollar).
Important aspects of Star
Schema & Snow Flake Schema
•
In a star schema every dimension will have a primary key.
•
In a star schema, a dimension table will not have any parent table.
•
Whereas in a snow flake schema, a dimension table will have one or more parent
tables.
•
Hierarchies for the dimensions are stored in the dimensional table itself in
star schema.
•
Whereas hierarchies are broken into separate tables in snow flake schema. These
hierachies helps to drill down the data from topmost hierarchies to the
lowermost hierarchies.
Kareem, I like most of the content in your blog except the small irritating twitter bird, which roams around the page when we scroll. Can you remove it or move it somewhere permanently? Just a request
ReplyDeleteEID Mubarak!
Very nice and useful infromation
ReplyDeleteinformatica training , informatica training in bangalore, informatica online training, informatica online training in bangalore