> [!NOTE] ![[assets/wl_lwlock_perxactpredicatelist.png|256]] > > | | | > | :--- | :--- | > | **Wait Category** | LWLock | > | **Mechanism** | `SerializablePredicateListLock` | > | **Operations** | [[Operations/Table/SeqScan]], [[Operations/Index/IndexScan]] | > | **Resources** | [[Resources/RAM|Memory]], [[Resources/CPU|CPU]] | > > Contention on the **Parallel SSI Coordination Layer**. When a serializable transaction launches parallel workers, those workers must participate in the same dependency graph as the leader to ensure the serializable guarantee is maintained across the whole process group.