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Live connection and DirectQuery comparison

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Live connection is a way of connecting a Power BI report to a published Power BI semantic model. DirectQuery is a method you can use to connect your semantic model to data. This article describes the main differences between these concepts.

Live connection

Live connection is a method that lets you build a report in Power BI Desktop without having to build a semantic model for it. When you create your report in Power BI Desktop, you can connect it to a semantic model that already exists. A live connection allows you to rely on existing data, which can be updated without accessing the report.

Using live connection you can connect your report to one of the following data sources:

  • A semantic model that already exists in Power BI service

  • An Azure Analysis Services (AAS) database

  • An on-premises instance of SQL Server Analysis Services (SSAS)

DirectQuery

A Power BI semantic model can have data copied into it during a refresh operation, in what's called import mode. Or, the semantic model can dynamically request data from a data source it's connected to using a method called DirectQuery.

When using DirectQuery, your report uses Data Analysis Expression (DAX) queries to get data. After the semantic model receives the report's DAX query, it generates another set of queries that are run on your data source, to get the required data. If for example your data source is an SQL Server database, Power BI will generate SQL queries to get the data it needs. Other data sources may generate queries in other query languages.

DirectQuery is useful when:

  • You're working against data sources with a large volume of data

  • You want to use 'near real-time' data

You can also use DirectQuery with Analysis Services, as described in Using DirectQuery for Power BI semantic models and Analysis Services.

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For more information, check out the following resources: