The deal with (LSN) of oldest WAL which even now could possibly be essential by The patron of the slot and thus will not be immediately removed through checkpoints unless this LSN will get at the rear of in excess of max_slot_wal_keep_size from The present LSN. NULL Should the LSN https://edgarqrpmj.pointblog.net/What-Does-PG-Slot-RO-Mean--56483142