Hi Atul Start by looking at the current WAL LSN and insert LSN. The pg_current_wal_lsn is the location of the last write. The pg_current_wal_insert_lsn is the logical location and reflects data in the buffer that has not been written to disk. There is also a flush value that shows what has been written to durable storage.
[postgres] # select pg_current_wal_lsn(), pg_current_wal_insert_lsn(); pg_current_wal_lsn | pg_current_wal_insert_lsn --------------------+--------------------------- 76/7D000000 | 76/7D000028 (1 row) Although you can guess the name of the WAL file based on the above output, it is best to use the pg_walfile_name function. [postgres] # select pg_walfile_name('76/7D000028'); pg_walfile_name -------------------------- 00000001000000760000007D (1 row) For details visit following link : https://www.crunchydata.com/blog/postgres-wal-files-and-sequuence-numbers Thanks Kashif Zeeshan On Tue, Apr 8, 2025 at 4:44 PM Atul Kumar <akumar14...@gmail.com> wrote: > In streaming replication What is the way to check which "WAL file" is > currently in use in primary and in standby ? > > > Regards. >