> [!NOTE] ![[assets/wl_lwlock_serializablexacthash.png|256]] > > | | | > | :--- | :--- | > | **Wait Category** | LWLock | > | **Mechanism** | `SerializableXactHashLock` | > | **Operations** | [[Operations/Table/SeqScan]], [[Operations/Index/IndexScan]] | > | **Resources** | [[Resources/RAM|Memory]], [[Resources/CPU|CPU]] | > > **SSI Identity Discovery Bottleneck**. To detect conflicts between sessions, Postgres must quickly find the "Predicate List" and "Status" for any transaction ID encountered during a scan.