Reviewed by Aditya Kumar · Last reviewed 2026-03-25
**Purpose**: Removes files older than retention (default 7 days) that are no longer in current table state. Reclaims storage. **Why**: Delta keeps all file versions for time travel. Old files accumulate. VACUUM deletes reclaimable files. **Trade-off**: Removes time-travel...
Purpose: Removes files older than retention (default 7 days) that are no longer in current table state. Reclaims storage.
Why: Delta keeps all file versions for time travel. Old files accumulate. VACUUM deletes reclaimable files.
Trade-off: Removes time-travel capability beyond retention. Ensure no active time-travel queries.
Syntax: VACUUM table_name or VACUUM table_name RETAIN 168 HOURS.
Scalability Trade-offs: Expensive on huge tables; run during maintenance.
Cost Implications: Un-vacuumed = 2–5x storage. Schedule weekly.
Pro-Move: 'VACUUM after OPTIMIZE; 7-day retention for audit compliance.' Red Flag: VACUUM with 0 retention—breaking ongoing time-travel use.
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