> [!AddinShmemInit] > <table><tr><td rowspan="4" width="25%"><img src="assets/wl_lwlock_shmem_individual.png"></td><td><b>Wait Category</b></td><td>LWLock</td></tr><tr><td><b>Mechanism</b></td><td><code>AddinShmemInitLock</code></td></tr><tr><td><b>Operations</b></td><td><a href="Operations/Table/SeqScan">SeqScan</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"><b>Extension Resource Allocation Barrier</b>. Many Postgres extensions (such as <code>pg_stat_statements</code> or <code>pgvector</code>) require a fixed amount of shared memory to track their internal state.</td></tr></table>