Swappable Dimension

Swappable dimensions are used in data warehousing when you have multiple versions of a dimension and you want to switch between them for different types of analysis. This concept is particularly useful in scenarios where different perspectives or classifications are needed for the same underlying data.

Key Components

Fact Table: SalesFact

Contains measures like QuantitySold and TotalSalesAmount Has a foreign key (ProductID) that can link to either product dimension

Multiple Dimension Tables:

• StandardProductDimension
• SeasonalProductDimension

Common Identifier:

Both dimension tables share ProductID as their primary key

Different Attributes:

• StandardProductDimension: Category, SubCategory, Brand
• SeasonalProductDimension: Season, HolidayTheme, WeatherAppropriate

Functionality:

Allows switching between different product perspectives in analyses Enables querying sales data using either standard or seasonal product attributes

Benefits:

• Flexibility in reporting and analysis
• Accommodates different business needs or seasonality
• Optimizes storage by separating rarely-used attributes

Use Case Example:

• Use StandardProductDimension for regular inventory analysis
• Switch to SeasonalProductDimension for holiday sales planning

Implementation Note: Requires careful ETL processes to ensure data consistency across dimensions.