Columnar storage.

also: column-oriented storage · column store · columnar · Parquet · column-oriented

Storing 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.

also: column-oriented storage · column store · columnar · Parquet · column-oriented

Storing each column's values together on disk, so analytical queries read only the columns they need and compress far better.

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.