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Re: pg_stat_replication write_lsn documentation ambiguity? - Mailing list pgsql-admin

From Rui DeSousa
Subject Re: pg_stat_replication write_lsn documentation ambiguity?
Date
Msg-id E3BAC71E-A92E-48C6-BA0D-11E6853BE80B@crazybean.net
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In response to pg_stat_replication write_lsn documentation ambiguity?  (Ron Johnson <ronljohnsonjr@gmail.com>)
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On Mar 26, 2025, at 12:35 PM, Ron Johnson <ronljohnsonjr@gmail.com> wrote:



write_lsn pg_lsn
Last write-ahead log location written to disk by this standby server
flush_lsn pg_lsn
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!

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.

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