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Microsoft Power BI Updates Blog

What’s New in SQL Server 2025 Analysis Services

Headshot of article author Denyse Niwenshuti

June 9, 2025

The preview of SQL Server 2025 is now available at aka.ms/getsqlserver2025! This preview includes many exciting enhancements for SQL Server Analysis Services (SSAS).

SQL Server 2025 Analysis Services (SSAS) introduces a range of enhancements across performance, modeling, diagnostics, and DAX capabilities. This blog highlights the most impactful updates for enterprise BI professionals and developers.

Content:

Performance Improvements

DAX Functions and Capabilities

Additional Features

Deprecated Features and Breaking Changes

Next Steps

Performance Improvements

Models with calculation groups and format strings in Excel

We have made significant performance improvements for MDX queries on models with Calculation Groups and Format Strings to reduce memory usage and improve responsiveness! The latest changes will greatly improve the performance and reliability of operations in Analyze in Excel on models that include one or both of:

  • Dynamic Format Strings for Measures
  • Calculated Items with Format Strings

For more details, refer to the Dynamic format strings documentation.

Parallel Query Execution for DirectQuery

Improved parallelism in DirectQuery mode enables faster response times for complex queries. The fundamental idea is to maximize query performance by parallelizing multiple queries to the datasource for a single DAX query. This query parallelization reduces the impact of data source delays and network latencies on query performance.

For more details, refer to the Query parallelization helps to boost the Power BI dataset performance in DirectQuery mode blog post.

Horizontal Fusion

SSAS 2025 incorporates the latest version of Horizontal Fusion, a query performance optimization that reduces the number of SQL queries generated by DAX, improving DirectQuery efficiency.

For more details, refer to the Announcing “Horizontal Fusion,” a query performance optimization in Power BI and Analysis Services blog post.

DAX Functions and Capabilities

Visual Calculations

The way you write DAX changes today with the introduction of visual calculations! Visual calculations are DAX calculations that are defined and executed directly on a visual. A visual calculation can refer to any data in the visual, including columns, measures, or other visual calculations. This approach removes the complexity of the semantic model and simplifies the process of writing DAX. You can use visual calculations to complete common business calculations such as running sums or moving averages. Visual calculations make it easy to do calculations that were previously very hard or even almost impossible to do.

To learn more about how to enable and use visual calculations, visit Visual calculations overview documentation.

Value Filter Behavior

We are introducing a new option to control value filter behavior. By enabling the “Independent Value Filters” setting, users can prevent the automatic combining of multiple filters on the same table into a single coalesced filter. This change offers greater flexibility, allowing for more precise and independent filtering to meet specific modeling needs, thereby enhancing the accuracy and control of data queries. To set this property for SSAS, you can use the Tabular Object Model or TMSL based on the ValueFilterBehavior property.

For more details, refer to the Value filter behavior documentation.

Selection Expressions for Calculation Groups

Selection expressions allow fine-tuned control over how calculations behave when certain conditions are met. They introduce additional logic for handling cases where multiple calculation items are selected or when no specific selection is made on a calculation group.

For more details, refer to the Calculations groups documentation.

DAX Functions Improvements

SSAS 2025 includes support for multiple new DAX functions and improvements including:

  • LINEST and LINESTX: These two functions perform linear regression, leveraging the Least Squares method, to calculate a straight line that best fits the given data and return a table describing that line. These functions are especially useful in predicting unknown values (Y) given known values (X).
  • INFO Functions: The existing TMSCHEMA DMVs are now available as a new family of DAX functions, which allows querying metadata about semantic models directly within DAX, offering integration with other DAX functions for enhanced diagnostics and analysis.
  • APPROXIMATEDISTINCTCOUNT: This function is currently available for DirectQuery mode and returns an estimated count of unique values in a column by invoking a corresponding aggregation operation in the data source, which is optimized for query performance.
  • Window Functions: This function retrieves a slice of results using absolute or relative positioning. The WINDOW function will make it easier to perform calculations such as adding a running total, moving average or similar calculations that rely on selecting a range of values. It also comes with two helper functions called ORDERBY and PARTITIONBY.
  • MINX/MAXX: We have added an optional variant parameter to MINX and MAXX DAX functions. Traditionally, these functions ignore text and Boolean values when there are variants or mixed data types, such as text and numeric. Now with the new optional variant parameter set to TRUE, the functions will consider the text values.

Additional Features

Client Library Updates

Customers are encouraged to upgrade to the latest Analysis Services libraries to benefit from performance, reliability and functionality improvements such as binary XML support, TMDL serialization, and more. Specifically, we have switched XMLA-based communication from plain text XML to binary XML and enabled compression for the .NET client libraries.

For more details, visit improving the communication performance of xmla based tools blog. You can also always find the latest client libraries versions on the Analysis Services client libraries download page.

Unicode Character Handling Enhancements

SSAS now supports updated Unicode standards by providing Unicode surrogate pair support for character standards such as the Chinese government standard GB18030 in DAX.

Execution Metrics for Diagnostics

Execution metrics are now exposed via XEvents and Profiler traces, enabling customers to analyze query performance more effectively.

Deprecated Features and Breaking Changes

Excel PowerPivot for SharePoint Deprecated

We have removed Excel PowerPivot for SharePoint mode from the installer. This feature was deprecated in prior releases and is no longer supported.

SQL Client Assembly Update

SSAS 2025 now uses a newer SQL client library. Customers may need to update model definitions to reflect the new provider name (Microsoft.Data.SqlClient).

Next Steps