You can
use the Optimize option to materialize calculations in your extract. When calculations are materialized, certain calculations are computed in advance and its values stored in the extract. Depending on the complexity of the calculations used in your extract, this can potentially speed up future queries by allowing Tableau to compute certain calculations in advance. Tableau can then use the precomputed value rather than computing the value each time a query against a calculation is made.

If the formula for a calculation that Tableau has already materialized changes or the calculation is deleted from the data source, the materialized calculation is removed from the extract until you use the Optimize option again.

When to materialize calculations

You should not use the Optimize option for all your extracts. Instead, try this option only when the query performance of your extract is slow as a result of complex calculations, such as string manipulations and regular expressions.

Materialize calculations

To materialize calculations in your extract, do the following:

In Tableau Desktop, select the extract data source from the Data menu.

Select Extract > Optimize.

Calculations that cannot be materialized

The following calculations cannot be materialized:

Calculations that use unstable functions such as NOW() and TODAY()

Calculations that use external functions such as RAWSQL and R