> [!info] ParallelHashJoin > <table><tr><td rowspan="4" width="25%"><img src="assets/wl_lwlock_parallel_hash_join.png"></td><td><b>Wait Category</b></td><td>LWLock</td></tr><tr><td><b>Mechanism</b></td><td><code>ParallelHashJoinLock</code></td></tr><tr><td><b>Operations</b></td><td><a href="Operations/Joins/HashJoin">HashJoin</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>Shared Hash Table Contention</b>. Parallel workers are waiting to acquire the lightweight lock protecting access to the shared hash table during the build or probe phase of a parallel hash join. (Analogized by chameleons in hard hats building a wobbly modular shelving unit, waiting for turns to slot in books).</td></tr></table>