> [!NOTE] ![[assets/wl_lwlock_multixacttruncation.png|256]] > > | | | > | :--- | :--- | > | **Wait Category** | LWLock | > | **Mechanism** | `MultiXactTruncationLock` | > | **Operations** | [[Operations/Table/SeqScan]], [[Operations/ResultSet/Materialize]] | > | **Resources** | [[Resources/RAM|Memory]], [[Resources/CPU|CPU]] | > > This wait event represents a **Log Retention Barrier**. As the cluster advances through MultiXact IDs (MXIDs), old segments of the MultiXact logs are no longer needed and can be safely deleted to reclaim disk space.