> [!MultiXactTruncation] > <table><tr><td rowspan="4" width="25%"><img src="assets/wl_lwlock_multixact_truncation.png"></td><td><b>Wait Category</b></td><td>LWLock</td></tr><tr><td><b>Mechanism</b></td><td><code>MultiXactTruncation</code></td></tr><tr><td><b>Operations</b></td><td><a href="Operations/Table/Vacuum">Vacuum</a></td></tr><tr><td><b>Resources</b></td><td><a href="Resources/RAM">Memory</a>, <a href="Resources/Disk">Disk</a></td></tr><tr><td colspan="3">Contention on <b>Group Lock Cleanup</b>. This lock is acquired when the engine needs to truncate (delete) old MultiXact SLRU files that are no longer needed, typically during a vacuum or checkpoint.</td></tr></table>