Power BI Limitations and Known Issues

This section describes limitations and known issues of AtScale's support for the Power BI SQL Server Analysis Services Connector.

Microsoft Limitations

Client-Side Modeling and Custom DAX Expressions

Microsoft Power BI does not support client-side modeling features or custom DAX expressions for Live Connections to Multi-Dimensional data sources such as Microsoft SQL Server Analysis Services and AtScale. To create report-scoped calculations, you must either connect to AtScale from Power BI in Tabular mode, or configure the AtScale engine to run in tabular mode. For more information, see Configuring Connections.

Client-Side Multi-Datasource Modeling

Microsoft Power BI does not support multi-data source modeling with Live Connections to Multi-Dimensional data sources such as Microsoft SQL Server Analysis Services and AtScale. If you are interested in using client-side multi-datasource modeling with AtScale 2022.3.0 or later, ask your Account Executive about participating in AtScale's Tabular DAX Beta program.

Access to Cube-Side Drill-Through Sets

Microsoft Power BI does not support access to cube-side multi-dimensional Drill-through Sets, known as 'Actions' in SSAS, with Live Connections to Multi-Dimensional data sources such as Microsoft SQL Server Analysis Services and AtScale. There are no AtScale enhancements scheduled for this issue because it is a Microsoft Power BI limitation.

Decomposition Tree visualization

With respect to connections, Microsoft classifies AtScale as an 'On-premise SQL Server Analysis Services' data source. Microsoft Power BI does not support the Decomposition Tree visualization from such sources. For details, see Known Limitations.

Key Influencers visualization

With respect to connections, Microsoft classifies AtScale as an 'On-premise SQL Server Analysis Services' data source. Microsoft Power BI does not support the Key Influencers visualization from such sources. For details, see Considerations and Troubleshooting.

For more information regarding Power BI's SSAS MD data source connection capabilities and limitations, see Connect to SSAS multidimensional models in Power BI Desktop.

Queries with large numbers of chained ISBLANK constraints

When using the Legacy DAX dialect, Power BI generates queries with large numbers of non-user specified ISBLANK function calls, which can slow down query processing. If a cube is affected by this issue, you can connect to it using either the SuperDAX MD or DAX Tabular dialects; for more information, see Using SuperDAX MD and Configuring Connections.

Alternatively, you can use the following workaround:

  1. Make sure you are an Organisation Administrator or Super User.
  2. Access the cube settings; for details, see Cube Level Configuration Settings.
  3. Select the cube affected by the issue.
  4. Locate the query.language.dax.bypassIsBlank setting and set it to True.
  5. Save your changes.

Note: When this setting is enabled, the cube will not be able to service intentional ISBLANK filters.

Known AtScale Issues

Measure Filtering

AtScale supports Power BI filters on Measure. Consider the following:

  • To use this feature, set the Engine setting QUERY.FACTLESS.IGNOREINCIDENTALFILTER = FALSE and restart the Engine.
  • Power BI Measure filtering is NOT supported on AtScale Calculated Measures that use dimension modification functions, such as lag, parallelperiod, periodstodate, parent, siblings, children, descendants, ancestor, and so on.
  • To allow dimensionally-modified measure filter queries, you can use the query.language.dax.blockDimModifiedMeasureFilters engine setting. For details, see Changes related to upgrades.

Scatter chart is not displayed when using SuperDAX MD

When the connection from Power BI to AtScale is configured to use the SuperDAX MD dialect, trying to use a Scatter chart in Power BI leads to "Can't display the visual" error. (ATSCALE-9570)

Matrix visualization is not supported for CDP Impala 3.x

Matrix Visualization in Power BI is not supported for CDP Impala version 3.x. (ATSCALE-9552)

Date Filtering

Trying to apply a filter based on a column of type Date could lead to issues with the visualization. As a work-around, you can convert the type from Date to DateTime or Timestamp using a calculated column, and then adjust the attribute column binding.(ATSCALE-6703)

Is-Not Filters Result in Incorrect Grand Totals for PeriodsToDate Calculated Measures in Some Situations

Power BI visualizations display incorrect Grand Total values when Is-Not filters are applied to calculated measures that use the PeriodsToDate function. As a workaround, you can use the DatesPeriodsToDate function on calculated measures, for which Power BI displays correct Grand Total values.

ATSCALE-20118

Calculation Group Totals Do Not Display in Some Situations

Calculation group totals are not displayed in Power BI visualizations that have multiple measures selected and that are filtered by a subset of the calculations.

ATSCALE-20030