> [!SyncRep] > <table><tr><td rowspan="4" width="25%"><img src="assets/wl_ipc_syncrep.png"></td><td><b>Wait Category</b></td><td>IPC</td></tr><tr><td><b>Mechanism</b></td><td><code>SyncRepWaitForLSN</code></td></tr><tr><td><b>Operations</b></td><td><a href="Operations/Tuple/ModifyTable">ModifyTable</a>, <a href="Operations/Distributed/Redistribute">Redistribute</a></td></tr><tr><td><b>Resources</b></td><td><a href="Resources/Network">Network</a>, <a href="Resources/disk IO">disk IO</a></td></tr><tr><td colspan="3">That the primary database is stalled by its <b>Synchronous Replication</b> requirements. Even though the data is safely written to the local disk, the backend must wait for a signal from the remote standby confirming that the WAL data has been received (and potentially written or applied, depending on the <code>synchronous_commit</code> level).</td></tr></table>