> [!ReplicationSlotDrop] > <table><tr><td rowspan="4" width="25%"><img src="assets/wl_ipc_replicationslotdrop.png"></td><td><b>Wait Category</b></td><td>IPC</td></tr><tr><td><b>Mechanism</b></td><td><code>ReplicationSlot</code></td></tr><tr><td><b>Operations</b></td><td><a href="Operations/Distributed/Redistribute">Redistribute</a></td></tr><tr><td><b>Resources</b></td><td><a href="Resources/disk IO">disk IO</a>, <a href="Resources/CPU">CPU</a></td></tr><tr><td colspan="3"><b>Replication Persistence Cleanup Barrier</b>. Before a slot can be dropped, the engine must ensure that no <code>WAL Sender</code> is currently attached to it and that all associated persistent state files in <code>pg_replslot/</code> can be safely deleted.</td></tr></table>