> [!WALCopyRead] > <table><tr><td rowspan="4" width="25%"><img src="assets/wl_io_walcopyread.png"></td><td><b>Wait Category</b></td><td>IO</td></tr><tr><td><b>Mechanism</b></td><td><code>pg_wal</code></td></tr><tr><td><b>Operations</b></td><td><a href="Operations/Distributed/Redistribute">Redistribute</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>Log Management Retrieval stall</b>. To minimize the overhead of file creation, Postgres "recycles" old WAL segments by copying them to new IDs or zeroing them out before they are reused for new transactions.</td></tr></table>