What is Kimball dimensional model?
The concept of Dimensional Modelling was developed by Ralph Kimball and consists of “fact” and “dimension” tables. A dimensional model in data warehouse is designed to read, summarize, analyze numeric information like values, balances, counts, weights, etc. in a data warehouse.
What are the types of dimensions in data warehouse?
In data warehousing there are 6 types of dimension:
- Normal dimension.
- Junk dimension.
- Split dimension.
- Text dimension.
- Stacked dimension.
- Distinct Attribute dimension.
What is outrigger dimension?
An outrigger is a dimension table or entity that is joined to other dimension tables in a star schema. Outriggers are often used when a dimension table or entity is referenced by another dimension. The primary key of an outrigger is referenced by the foreign key of a dimension table or entity.
Is dimensional modeling dead?
Dimensional modeling is not dead; far from it. As the data landscape evolves toward more complexity, dimensional modeling continues to allow more people to access and use the information buried in the mountains of data generated every day.
What is Kimball data warehouse?
Kimball defines data warehouse as “a copy of transaction data specifically structured for query and analysis”. Dimensional modelling focuses on ease of end-user accessibility and provides a high level of performance to the data warehouse.
What is a mini dimension?
Mini-dimensions contain the rapidly changing attributes of the original dimension and are treated as a stand-alone dimension. This dimension will band the attributes together instead of treating them as individual pieces of data. Here is a partial example of the data which may be stored in the mini-dimension table.
What is a shrunken dimension?
A shrunken dimension entity can be defined when a fact entity holds measures that are captured at a higher level of granularity of the concerned dimension than in other, more granular fact entities. A shrunken dimension entity does not coexist with the dimension entity, of which it is a subset, on the same fact entity.
What is Kimball modeling?
The name “Kimball” is synonymous with dimensional modeling. The Kimball Group established the vocabulary and techniques for dimensional modeling, and these techniques show up in today’s popular business intelligence, database, and ETL tools. An excellent dimensional model, or star schema, is the foundation of an excellent data warehouse.
What is the Kimball Group?
Ralph Kimball introduced the data warehouse/business intelligence industry to dimensional modeling in 1996 with his seminal book, The Data Warehouse Toolkit . Since then, the Kimball Group has extended the portfolio of best practices.
Can a customer have multiple addresses in Kimball?
A customer can have multiple addresses: home, work, vacation,etc. In Kimball data warehouse, would I utilize a bridge table to go between Customer and Customer Address information? (a) So [DimCustomer] to [DimCustomerAddressBridge] to [DimAddress] Table?
Where did the home city field for Ralph Kimball change?
Suppose we are notified that the Home City field for Ralph Kimball in the Employee dimension has changed from Santa Cruz to Boulder Creek as of today. Furthermore, we are advised that this is an error correction, not an actual change of location.
