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Getting ready
- Choose a database to serve as the source for the DirectQuery data model.
- Create a logical and physical design of the fact and dimension tables of the model including the relationship keys and granularity of the facts.
- Determine or confirm that each fact-to-dimension relationship has referential integrity.
- Providing this information to the DirectQuery model allows for more performant inner join queries.
- Create view objects in the source database to provide efficient access to the dimensions and facts defined in the physical design.
Be aware that DirectQuery models are limited to a single source database and not all databases are supported for DirectQuery. If multiple data sources are needed, such as SQL Server and and Oracle or Teradata and Excel, then the default Import mode model, with scheduled refresh to the Power BI Service, will be the only option.