Calculated fields, especially when complex, can also give Tableau a hard time. However, you can counter this by trying to implement the following:
- If there's a calculation metric that's frequently used in your workbook, consider creating it directly in the database, and not as a table calculation. This can save computational resources Tableau would otherwise have to invest in creating the views.
- Disaggregated (row-level) calculations can be very demanding. Try to aggregate your measures when creating calculated fields.
- When alternatives are available, consider using functions that are faster to execute in your calculated fields. For example:
- Try replacing IF-ELSE statements with CASE-WHEN statements
- Try to avoid nested IF statements
- Try to skip using LOD expressions if not necessary, since they can be computationally demanding