How Direct Query Caches data - Power BI - SQL datasource

[mak82pk]

Hi I need to know once the report is published the whole cache is refreshed with new data or it compares and updates the records in the cache? 

https://powerbi.microsoft.com/en-us/documentation/powerbi-desktop-directquery-about/

Please read the bold text below

DirectQuery connections

When using Get Data in Power BI Desktop to connect to a data source, and you choose DirectQuery, the behaviour of that connection is as follows:

• During the initial Get Data experience, the source is selected. For relational sources, this means a set of tables are selected and each still define a query that logically returns a set of data. For multidimensional sources like SAP BW, only the source is selected.
• However, upon load, no data will actually be imported into the Power BI store. Instead, upon building a visual within Power BI Desktop, queries will be sent to the underlying data source to retrieve the necessary data. The time then taken to refresh the visual will depend on the performance of the underlying data source.
• Any changes to the underlying data will not be immediately reflected in any existing visuals. It is still necessary to Refresh, whereupon the necessary queries will be resent for each visual, and the visual updated as necessary.
• Upon publishing the report to the Power BI service, it will again result in a Dataset in the Power BI service, just as for import. However, no data is included with that dataset.
• When opening an existing report in the Power BI service, or authoring a new one, the underlying data source is again queried to retrieve the necessary data. Depending upon the location of the original data source, it might be necessary to configure an On-premises data gateway, just as is needed for Import mode if the data is refreshed.
• Visuals, or entire report pages, can be pinned as Dashboard tiles. To ensure that opening a dashboard will be fast, the tiles are automatically refreshed on a schedule (for example, every hour). The frequency of this refresh can be controlled, to reflect how frequently the data is changing, and how important it is to see the very latest data. Thus, when opening a dashboard, the tiles will reflect the data as of the time of the last refresh, and not necessarily the very latest changes made to the underlying source. An open dashboard can always be Refreshed to ensure it is up-to-date.

[v-ljerr-msft · Accepted solution]

Hi @mak82pk,

Hi I need to know once the report is published the whole cache is refreshed with new data or it compares and updates the records in the cache? 

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For DirectQuery mode, there is no any data included in the dataset on Power BI service, but a direct connection between Power BI and the database. When you interact with a visualization, queries are sent from Power BI directly to the database, and query results will be updated on the visualization.

To enhance the performance, dashboard tiles are cached and periodically refreshed. When a cache refresh happens, queries will be resent from Power BI directly to the database again for all visualizations/tiles, and query results will be updated on all the visualizations. 

Regards

[mak82pk]

I am working on Power BI Report. Is it same for report as well

[v-ljerr-msft]

Hi @mak82pk,

Yes, it is the same for both reports and dashboards on Power BI service. 

Regards

[Anonymous]

Hi

I want to set up  scheduled cache refresh manually but seeing it disabled (greyed out) in power bi service.

Can anyone tell me  how to enable this  option for direct queries