![[assets/wl_io_walwrite.png|256]] - **Description**: Indicates that PostgreSQL is waiting for the write-ahead log buffers to be written to a WAL file on disk. High `WALWrite` waits can indicate an overloaded disk subsystem or high transaction volume exceeding the storage throughput. - **Operations**: - [[Operations/ModifyTable]] - **Resources**: [[Resources/disk IO]], [[Resources/CPU|CPU]]