> [!DataFileWrite] > <table><tr><td rowspan="4" width="25%"><img src="assets/wl_io_datafilewrite.png"></td><td><b>Wait Category</b></td><td>IO</td></tr><tr><td><b>Mechanism</b></td><td><code>FileWrite</code></td></tr><tr><td><b>Operations</b></td><td><a href="Operations/Table/SeqScan">SeqScan</a>, <a href="Operations/Tuple/ModifyTable">ModifyTable</a>, <a href="Operations/ResultSet/Materialize">Materialize</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">This wait event represents a synchronous <b>Storage Writing Stall</b>. While Postgres attempts to perform most writes in the background (via the checkpointer or bgwriter), backend processes will experience this event if they are forced to "clean" a dirty buffer themselves to make room for new data (a "backend write") or during bulk operations like <code>VACUUM FULL</code>.</td></tr></table>