Fact Table

Fact Table | Star Schema: The centralized table in a star schema is called as FACT table. A fact table typically has two types of columns: those that contain facts and those that are foreign keys to dimension tables. The primary key of a fact table is usually a composite key that is made up…

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Designing Snowflake Schema

Snowflake Schema: A snowflake schema is a term that describes a star schema structure normalized through the use of outrigger tables. i.e dimension table hierarchies are broken into simpler tables. In Star Schema example we had 4 dimensions like location, product, time, organization and a fact table (sales). In Snowflake schema, the example diagram shown…

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Designing Star Schema

Star Schema: General Information In general, an organization is started to earn money by selling a product or by providing service to the product. An organization may be at one place or may have several branches. When we consider an example of an organization selling products throughout the world, the main four major dimensions are…

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Time Dimension

In a relational data model, for normalization purposes, year lookup, quarter lookup, month lookup, and week 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 TIME DIMENSION for performance and slicing data. This dimensions helps to find the sales…

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Organization Dimension

In a relational data model, for normalization purposes, corporate office lookup, region lookup, branch lookup, and employee 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 ORGANIZATION DIMENSION for performance and slicing data. This dimension helps us to find the…

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Product Dimension

In a relational data model, for normalization purposes, product category lookup, product sub-category lookup, product lookup, and and product feature lookups are are not merged as a single table. In a dimensional data modeling(star schema), these tables would be merged as a single table called PRODUCT DIMENSION for performance and slicing data requirements. Example of…

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Dimension Tables

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…

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Data Warehouse and Data Mart

A Data Warehouse is a relational/multidimensional database that is designed for query and analysis rather than transaction processing. A data warehouse usually contains historical  data that is derived from transaction data. It separates analysis workload from transaction workload and enables a  business to consolidate data from several sources. In addition to a relational/multidimensional database, a…

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