> [!ControlFileSync] > <table><tr><td rowspan="4" width="25%"><img src="assets/wl_io_controlfilesync.png"></td><td><b>Wait Category</b></td><td>IO</td></tr><tr><td><b>Mechanism</b></td><td><code>ControlFileSync</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">This wait event represents a critical <b>Integrity Barrier</b> in the Postgres architecture. The <code>pg_control</code> file contains the "Master State" of the database cluster, including the current Checkpoint LSN, the system identifier, and the state of transaction ID wraparound.</td></tr></table>