> [!NOTE] ![[assets/wl_lwlock_parallelbtreescan.png|256]] > > | | | > | :--- | :--- | > | **Wait Category** | LWLock | > | **Mechanism** | `ParallelBtreeScanLock` | > | **Operations** | [[Operations/Index/IndexScan]] | > | **Resources** | [[Resources/RAM|Memory]], [[Resources/CPU|CPU]] | > > Synchronization stall during **Parallel Index Traversal**. In a parallel-aware index scan, workers must coordinate their movement through the B-tree to ensure that each block is processed exactly once and that results are returned in a consistent manner.