Columnar storage.
also: column-oriented storage · column store · columnar · Parquet · column-orientedStoring each column's values together on disk, so analytical queries read only the columns they need and compress far better.
the two-minute refresher
- SUM(revenue) on a row store reads every column of every row.
- A column store reads just the revenue column: 75% less I/O in the lesson's example.
- Similar values side by side compress well and suit vectorised (SIMD) processing.
- Formats: Parquet, ORC; engines: ClickHouse, BigQuery, Redshift.