Database Management Systems · Analytics

Data warehousing and OLAP

A separate database optimized for big analytical queries over historical data, not fast day-to-day transactions.

Also known as: OLAP, data warehouse, star schema.

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Learn first

• SQL aggregation and grouping: Collapsing many rows into one summary number per group, like a total or average per category.

Related topics

• NoSQL data models: Alternatives to tables: documents, key-value pairs, wide columns, or graphs, each suited to a different access pattern.
• Views and materialized views: A saved query that acts like a table; materialized means the result is actually stored, not recomputed each time.
• Normalization: Splitting tables so each fact lives in exactly one place, to avoid update anomalies.