> [!BufferMapping] > <table><tr><td rowspan="4" width="25%"><img src="assets/wl_lwlock_buffers_hamster.png"></td><td><b>Wait Category</b></td><td>LWLock</td></tr><tr><td><b>Mechanism</b></td><td><code>BufferMappingLock</code></td></tr><tr><td><b>Operations</b></td><td><a href="Operations/Table/SeqScan">SeqScan</a>, <a href="Operations/Index/IndexScan">IndexScan</a>, <a href="Operations/Page/BitmapHeapScan">BitmapHeapScan</a></td></tr><tr><td><b>Resources</b></td><td><a href="Resources/RAM">Memory</a>, <a href="Resources/CPU">CPU</a></td></tr><tr><td colspan="3">A backend process is blocked while searching the <b>Shared Buffer Hash Table</b> for a specific block. Because the cache is partitioned to allow concurrent lookups, multiple <code>BufferMappingLocks</code> exist (typically 128 or more).</td></tr></table>