Theory
Same three layers, three vocabularies
Snowflake, Databricks and BigQuery look wildly different in their docs, but under the marketing they share the same three-layer anatomy. Learn the layers once and every vendor's jargon becomes translation, not new learning:
- Storage layer — Where bytes durably live, in open or proprietary columnar format on object storage. Snowflake: proprietary micro-partitions in its managed storage. Databricks: Delta Lake (Parquet + a transaction log) in your lake. BigQuery: the Capacitor columnar format in Google-managed Colossus storage.
- Compute layer — The engines that scan storage. Snowflake: virtual warehouses (T-shirt-sized clusters). Databricks: clusters / SQL warehouses running Spark + the Photon engine. BigQuery: slots (serverless units of CPU drawn from a shared or reserved pool).
- Services / metadata layer — The brain: query optimiser, security & RBAC, transactions, the catalogue. Snowflake: the Cloud Services layer. Databricks: the control plane + Unity Catalog. BigQuery: the Dremel engine + IAM + the BigQuery metadata service.
Use Case Example: 'Grant analysts read on the sales table' is the services layer everywhere — only the syntax differs (GRANT SELECT vs Unity Catalog grants vs IAM roles). 'Make this query faster' is the compute layer — resize the warehouse, scale the cluster, or buy more slots. Knowing which layer a problem lives in tells you which knob to turn on any of the three platforms.