> [!NOTE] ![[assets/wl_lwlock_multixactmemberbuffer.png|256]] > > | | | > | :--- | :--- | > | **Wait Category** | LWLock | > | **Mechanism** | `MultiXactMemberControlLock` | > | **Operations** | [[Operations/Tuple/ModifyTable]], [[Operations/Table/SeqScan]] | > | **Resources** | [[Resources/RAM|Memory]], [[Resources/CPU|CPU]] | > > **Shared Lock Metadata Cache Barrier**. While the `IO:MultiXactMemberBuffer` event represents the actual time spent waiting for the disk, this `LWLock` version represents the time spent waiting for the *permission* to access the memory-resident copy of that data.