📊 Virtual Columns in Fact Tables

What

Virtual columns let you define a computed SQL expression once on a fact table — a ratio, a bucketed range, a boolean flag — and reference it by name from any metric, filter, or dimension built on that table.

Why

Metrics often depend on values a warehouse doesn't store: a ratio, a bucketed range, a boolean flag. Producing them has required either a schema change or the same SQL expression repeated in every metric that needs it.

A virtual column defines that expression once on the fact table. Any metric, filter, or dimension on that table can reference it by name, and nothing changes in the warehouse.

How

• Open a fact table and go to Virtual Columns
• Define the column name and SQL expression; it becomes available as a field everywhere that fact table is used
• No warehouse changes required