One Big Table (OBT)

Concepts: dmOneBigTable

Flatten Everything Into One Table One Big Table (OBT) is exactly what it sounds like: pre-join all your dimensions into the fact table and serve everything from a single wide table. No JOINs at query time. Every column an analyst might need is on the same row. Simple, fast, and easy to understand. OBT is a consumption pattern, not a source-of-truth pattern. You build the OBT from normalized source tables. The OBT is a derived, denormalized view optimized for a specific set of queries. If the source data changes, you rebuild the OBT. OBT works well for BI tools that struggle with JOINs (some Tableau configurations, Google Sheets connected to BigQuery). It also works for ML feature tables where the model needs a flat input. It does not work well as a general-purpose analytical model because