Table Calculations Shouldn’t Require a PhD
The Compute Using Confusion
“I just want a running total by month within each region. Why does changing ‘Compute Using’ completely change my numbers?”
“RANK() gives me the right ranking until I add a filter, then it re-ranks from 1 again. How do I keep the original rank?”
“Addressing and partitioning — I’ve read every blog post and I still can’t get my percent-of-total to work correctly across sub-categories.”
Why Table Calculations Trip Up Everyone
Table calculations are computed after the query returns — they operate on the result set in Tableau, not in the database. That means their behavior is tightly coupled to your view layout: which dimensions are on rows vs. columns, the sort order, and the filter configuration. Change any of these and your table calc can produce completely different results.
The “Compute Using” setting controls addressing (the direction of computation) and partitioning (the groups within which it computes). Getting this right requires understanding your exact view structure — something no generic AI assistant can see.
How VizWhiz Makes Table Calcs Understandable
VizWhiz extracts your worksheet structure — dimensions on rows, dimensions on columns, the mark type, filters, and existing table calculations. When you ask about a running total or ranking issue, the AI understands exactly how your view is laid out.
- Explains addressing vs. partitioning in terms of your actual dimensions
- Shows why “Compute Using” changes your results and which setting is correct
- Helps convert quick table calcs to custom calculations for more control
- Identifies when an LOD expression would be more reliable than a table calculation