> [!CheckpointerShutdown] > <table><tr><td rowspan="4" width="25%"><img src="assets/wl_activity_checkpointershutdown.png"></td><td><b>Wait Category</b></td><td>Activity</td></tr><tr><td><b>Mechanism</b></td><td><code>CheckpointerMain</code></td></tr><tr><td><b>Operations</b></td><td><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">The <b>Final Durability Barrier</b>. To ensure that the database can restart instantly without a long crash recovery process, Postgres must flush all "dirty" pages from shared memory to physical storage before the postmaster terminates.</td></tr></table>