Thread: pg_stat_replication write_lsn documentation ambiguity?
Last write-ahead log location written to disk by this standby server |
Last write-ahead log location flushed to disk by this standby server |
They both say "to disk". Should the write_lsn description be changed to "to the OS"?
Death to <Redacted>, and butter sauce.
Don't boil me, I'm still alive.
<Redacted> lobster!
On Mar 26, 2025, at 12:35 PM, Ron Johnson <ronljohnsonjr@gmail.com> wrote:
write_lsnpg_lsnLast write-ahead log location written to disk by this standby serverflush_lsnpg_lsnLast write-ahead log location flushed to disk by this standby serverThey both say "to disk". Should the write_lsn description be changed to "to the OS"?--Death to <Redacted>, and butter sauce.Don't boil me, I'm still alive.<Redacted> lobster!
It is understandable to me, especially in the context of write vs flush. Maybe to ‘to the WAL file” if ‘to disk’ is not clear.
From write() man page:
The write() system call attempts to write nbytes of data to the object
referenced by the descriptor fd
From sync() man page:
The sync() system call forces a write of dirty (modified) buffers in the
block buffer cache out to disk.