> [!WrapLimitsVacuum] > <table><tr><td rowspan="4" width="25%"><img src="assets/wl_lw_wraplimitsvacuum.png"></td><td><b>Wait Category</b></td><td>LWLock</td></tr><tr><td><b>Mechanism</b></td><td><code>WrapLimitsVacuumLock</code></td></tr><tr><td><b>Operations</b></td><td><a href="Operations/Table/SeqScan">SeqScan</a></td></tr><tr><td><b>Resources</b></td><td><a href="Resources/RAM">Memory</a>, <a href="Resources/CPU">CPU</a></td></tr><tr><td colspan="3">Contention on the <b>Cluster Safety Layer</b>. To prevent data corruption caused by Transaction ID counter rollover, Postgres must track the "Oldest Frozen XID" and "Oldest MultiXact." If a transaction attempts to proceed past the hard limit, the cluster will automatically shut down.</td></tr></table>