WHAT IT IS
Leading cloud warehouses include Snowflake, BigQuery, Redshift, Databricks SQL, and Microsoft Fabric. Data is modeled dimensionally (Kimball star schema) or normalized (Inmon) or in a Data Vault, then exposed to BI tools through a semantic layer that enforces metric definitions.
HOW IT WORKS
Where an operational database (OLTP) is tuned for many small transactions, a warehouse (OLAP) is tuned for few large queries — columnar storage, partition pruning, and result caching. Modern warehouses blur the line with lake access (external tables), streaming ingestion, and ML runtimes in the same engine.
WHEN TO USE
Choose a warehouse-centric architecture when reporting workloads dominate, when data sources are mostly structured, or when governed BI is the primary consumer. Choose a lakehouse when ML and semi-structured workloads are also first-class.