Free practice · ordering · medium

Practice

Order a safe grain check

Arrange the steps for verifying an order-level table grain.

Order extract · structure card

One row per order, with every field assigned a role

Observation
One completed or open order
Candidate key
order_id · complete and unique
Measure
revenue · quantitative · USD
Dimensions
order_date, region, refunded

The row grain and candidate key must be verified before revenue is summarized or tables are joined.

Arrange in the correct order
  1. 1. Document the verified grain
  2. 2. Investigate any duplicate or missing keys
  3. 3. Compare row count with distinct complete keys
  4. 4. Identify the candidate key
  5. 5. State what one row should represent