Build a semantic layer

Build a semantic layer

Turn a star schema into governed metrics that every dashboard and AI agent computes the same way.

Outcome: You can define simple, ratio and filtered metrics that stay correct at every level of aggregation.

1. 1

   Define your first governed metrics

   Write revenue and order count once, so every dashboard and AI agent computes them the same way.

   Define governed metrics · 12 min · instant checks

2. 2

   Ratio metrics and filters

   Average order value is revenue ÷ orders, not the average of a column. And cancelled orders don't count.

   Define governed metrics · 12 min · instant checks

3. 3

   Semi-additive and non-additive measures

   Stock on hand adds up across warehouses but not across days. Tell the semantic layer which dimension it must never sum over.

   Define governed metrics · 12 min · instant checks

4. 4

   Dimensions, hierarchies and time grains

   A metric can only be sliced by dimensions its fact table actually joins to. Declaring them is what stops a wrong answer before it is drawn.

   Define governed metrics · 12 min · instant checks

5. 5

   Metric governance: one name, one meaning

   Trust comes from one definition per name, descriptions that say what is in and out, and a named owner who settles disputes.

   Define governed metrics · 10 min · instant checks