Data warehouse

Dimensional Modeling in Data Warehouse

  • Dimensional modeling (DM) names a set of techniques and concepts used in data warehouse design. It is considered to be different from entity-relationship modeling (ER). Dimensional Modeling does not necessarily involve a relational database. It is a design technique for databases intended to support end-user queries in a data warehouse.
  • To overcome the performance issues for large queries in the data warehouse dimensional modeling is the best technique. It to provides a way to improve query performence for summary report without effecting data integrity.
  • The dimensional modeling consists of two types of tables having different characteristics. They are   
                        a) Dimensional Table
                        b) Fact Table
  • Dimensional modeling always uses the concepts of facts (measures), and dimensions (context). Facts are typically  numeric values that can be aggregated, and dimensions are groups of hierarchies and descriptors that define the facts.  
  • For example student marks is the fact, student name, student gender are the elements of dimensions.

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