Tableau performance issue with Tabular Object Model

0
votes

We have developed a model in Tabular Object Model(TOM), <= 3.5 GB in size., and built few Tableau Dashboard(s) on top of this model.

Each dashboard is built by dragging multiple sheets into one dashboard. All the sheets (dragged in one dashboard) fetch data from one fact table (of course it has relationships with Date and other related dimensions) in TOM.

Now, when we interact with Tableau dashboard, we see a performance degradation. When we checked the SQL profiler, Tableau is generating a huge query for almost every interaction that we have with the dashboard.

We checked the huge query and observed that it includes the DAX/query for almost all the measures in fact tables, irrespective of whether the fact table is used in the said dashboard or not.

We have verified the filter settings in the dashboard, the settings are applicable only for the sheets dragged in our dashboard, so there is no question of visualizations getting changed in other dashboards.

Ironically, we still see that Tableau is creating a huge query and incorporating all the DAX/queries and this results into performance impact.

Is there any way we can restrict this behavior?

2
ssas-tabulartableau-api
Are you using custom SQL in Tableau? If so, don’t – Alex Blakemore
If you database is well structured, you can enable some query optimizations by checking the “Database Enforces Referential Integrity” option under the Data menu. That allows join-culling, avoiding joining unused tables. – Alex Blakemore
No I am not using custom SQL, directly connecting to tabular model and dragging and dropping the measures/dimension columns – Joseph

2 Answers

0
votes

In case anyone else is having this issue, this is tied into Tableau not actually supporting SSAS Tabular, the connector you using is for SSAS Multidimensional so Tableau generates MDX queries against the DAX-based Tabular model.

This is also evident from Tableau's own techspecs site:

https://www.tableau.com/products/techspecs

"Microsoft SQL Server Analysis Services 2008 SP4 or later, multi-dimensional mode only* "

0
votes

Tableau's website at https://www.tableau.com/products/techspecs clearly states support for

"Microsoft SQL Server Analysis Services 2005 or later, non-tabular mode only*(incl. support for Kerberos)"