Performance tip: Use “Selected Fields” in Dashboard Actions

When you are trying to maximize performance in Tableau, particularly on a live connection, sometimes the smallest changes can make a big difference. All of your choices in Tableau Desktop eventually end up as a real live SQL query, which the database will have to interpret. The simpler the query, the easier the interpretation, and in most cases the quicker the results.

generated action

Tableau’s Dashboard Actions are amazing, and in the newer versions there is a quick little “Use as filter” button on each sheet in a Dashboard. This creates an Action in the Dashboard->Actions menu which is set to “All Fields” down at the bottom. This is incredibly convenient from a creation standpoint; however, it means that the selected values for every single dimension in the Source Sheet will be passed along as filters in the WHERE clause of the eventual SQL query. This includes categorical information which you are displaying: if you are showing Product Category, Product Sub-Category, and Product ID; all three will be sent in the eventual query.

Particularly when you are getting down to granular details, you really only need the most granular piece of information to be passed into the WHERE clause. For optimal performance, you really only want to pass in values for fields that are indexed in the database. In the previous example, presuming that a Product ID can only belong to one Category and Sub-Category, setting the Action to “Selected Fields” and choosing “Product ID” would simplify the query sent; hopefully Product ID is indexed and thus you get an incredibly quick lookup.

 

 

 

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