> [!BaseBackupWrite] > <table><tr><td rowspan="4" width="25%"><img src="assets/wl_io_basebackupwrite.png"></td><td><b>Wait Category</b></td><td>IO</td></tr><tr><td><b>Mechanism</b></td><td><code>pg_basebackup</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"><b>Bulk Write Throughput Bottleneck</b>. During a base backup, the engine must physically copy gigabytes (or terabytes) of data across the I/O bus.</td></tr></table>