Improvement: Increase the parallelism of external queries that can be executed by the modern Get Data experience in SSAS 2017 Tabular model

Applies to: SQL Server 2017 Developer on WindowsSQL Server 2017 Enterprise on WindowsSQL Server 2017 Enterprise Core on Windows

Symptoms


Consider the following scenario:

  • You create an SQL Server 2017 Analysis Services (SSAS 2017) tabular model on a powerful computer that has more than 6 cores.
  • You configure the Maximum Number of Connections property of the data source object in the tabular model database to a number that is much larger than 6.
  • You connect to the tabular model database by using the modern Get Data experience that is introduced in the latest SQL Server Data Tools (SSDT) and process a table that contains many partitions.

You may notice that only 6 partitions are processed in parallel which results in a slow performance.  

After you install this update you will notice the following:

  • This update increases the parallelism by removing the current limit of 6. 
  • The maximum parallelism of external queries that can be executed by the modern Get Data experience is determined by the Maximum Number of Connections property of the data source object in the tabular model database. 

Resolution


This improvement is included in the following cumulative update for SQL Server:

       Cumulative update 4 for SQL Server 2017

References


Learn about the terminology that Microsoft uses to describe software updates.