• The 'Lagging Vacuum' Alert in RisingWave indicates that there are files in the object store that are useless to RisingWave but have not been deleted.
• The alert is triggered when the count of unreferenced objects is high.
• The alert rules for 'Lagging Vacuum' in RisingWave may be too restricted, causing it to be triggered even in normal situations.
• As long as the count of unreferenced objects does not climb unbounded, the impact on performance should be minimal.

- The 'Lagging Vacuum' Alert indicates useless files in the object store.
- Triggered when count of unreferenced objects is high.
- Alert rules may be too restricted, causing false triggers.
- Minimal impact on performance if count of unreferenced objects is controlled.