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Data & Analytics · Advanced

VACUUM Command

A Delta Lake command that permanently deletes data files no longer referenced by the table and older than the retention threshold (7 days by default).

Definition

VACUUM reduces storage costs but removes the ability to time travel past the retention period. Shortening retention below 7 days requires disabling a safety check.

Example

VACUUM sales RETAIN 168 HOURS;

Exam tip

VACUUM limits time travel; set retention to cover your longest-running queries and recovery needs.

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