Multi-pass SQL

Question

Hi, I would like to know if Tableau supports Multi-pass SQL. Thanks,

Nikolay Gerasimov · Accepted Answer

Hello! @Ester B​  Tableau supports Multipass SQL, and it happens automatically when you do things like blend data from different sources or use complex calculations. For example, if you use fields from two different data sources, Tableau runs separate queries and then blends the results. It also happens when you calculate things like percent of total-one query gets the data, and another computes the total.  It is also possible to make any sql query via custom sql   Best Regards, Nikolay

Riku Hasebe · Answer

Hello, Yes, Tableau supports multi-pass SQL. This means it can run multiple SQL queries behind the scenes to handle complex calculations—like Level of Detail (LOD) expressions, data blending, or nested aggregations.  For example, if you're combining data from different sources or calculating values at different levels (like customer-level and region-level), Tableau will generate multiple queries and combine the results internally.  Just keep in mind that this can sometimes impact performance, especially with large datasets. Using database views or Tableau extracts can help improve speed.    Hope this helps!

Multi-pass SQL

Tableau Desktop & Web Authoring

関連学習

さらにヘルプを表示