> [!WALInsert] > <table><tr><td rowspan="4" width="25%"><img src="assets/wl_lwlock_wal_walinsert.png"></td><td><b>Wait Category</b></td><td>LWLock</td></tr><tr><td><b>Mechanism</b></td><td><code>WALInsertLock</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/RAM">Memory</a>, <a href="Resources/CPU">CPU</a></td></tr><tr><td colspan="3"><b>Serialization Pinch Point</b> at the start of the durability cycle. Before any backend can write its transaction data to the WAL buffers, it must first acquire a <code>WALInsert</code> lock to determine the exact byte position (LSN) where its record should be placed.</td></tr></table>