Dimension Table
Dimension table is one that describe the business entities of an enterprise, represented as hierarchical, categorical information such as time, departments, locations, and products. Dimension tables are sometimes called lookup or reference tables.

Location Dimension
In a relational data modeling, for normalization purposes, country lookup, state lookup, county lookup, and city lookups are not merged as a single table. In a dimensional data modeling(star schema), these tables would be merged as a single table called LOCATION DIMENSION for performance and slicing data requirements. This location dimension helps to compare the sales in one region with another region. We may see good sales profit in one region and loss in another region. If it is a loss, the reasons for that may be a new competitor in that area, or failure of our marketing strategy etc.

Example of Location Dimension: Figure 1.8

Country Lookup
Country Code Country Name DateTimeStamp
USA United States Of America 1/1/2005 11:23:31 AM

State Lookup
State Code State Name DateTimeStamp
NY New York 1/1/2005 11:23:31 AM
FL Florida 1/1/2005 11:23:31 AM
CA California 1/1/2005 11:23:31 AM
NJ New Jersey 1/1/2005 11:23:31 AM

County Lookup
County Code County Name DateTimeStamp
NYSH Shelby 1/1/2005 11:23:31 AM
FLJE Jefferson 1/1/2005 11:23:31 AM
CAMO Montgomery 1/1/2005 11:23:31 AM
NJHU Hudson 1/1/2005 11:23:31 AM

City Lookup
City Code City Name DateTimeStamp
NYSHMA Manhattan 1/1/2005 11:23:31 AM
FLJEPC Panama City 1/1/2005 11:23:31 AM
CAMOSH San Hose 1/1/2005 11:23:31 AM
NJHUJC Jersey City 1/1/2005 11:23:31 AM

Location Dimension
Location
Dimension Id		 Country
Name		 State
Name		 County
Name		 City
Name		 DateTime
Stamp
1 USA New York Shelby Manhattan 1/1/2005 11:23:31 AM
2 USA Florida Jefferson Panama City 1/1/2005 11:23:31 AM
3 USA California Montgomery San Hose 1/1/2005 11:23:31 AM
4 USA New Jersey Hudson Jersey City 1/1/2005 11:23:31 AM





Relational vs Dimensional       Product Dimension Example