When should I use row storage instead of columnar?
Row stores excel at OLTP (Online Transaction Processing): point lookups, single-row updates, and mixed read-write workloads. Retrieving one customer record by ID from a row store is fast because all columns for that row are adjacent on disk. Columnar stores penalize small reads and writes, making them ideal for OLAP (analytics) but poor choices for operational databases.
Answered in
Columnar Storage: Why Column Stores Beat Row Stores for AnalyticsColumnar storage reads only needed columns, skipping the rest. Dictionary encoding shrinks data 50–100×. Analytics queries go from minutes to milliseconds.
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