Re: Wait event names mismatch: oldserxid

[Michael Paquier]

On Fri, Feb 09, 2018 at 06:04:39PM +0530, Ashutosh Bapat wrote:
> Name for wait event "LWTRANCHE_OLDSERXID_BUFFERS" is printed as
> "oldserxid", but documentation at
> https://www.postgresql.org/docs/10/static/monitoring-stats.html does
> not have exact same event there. Instead it has
> 
> OldSerXidLock     Waiting to read or record conflicting serializable
> transactions.

I see two events defined here in the code of type LWLock dedicated to
oldserxid:
- OldSerXidLock which is a wait event defined as it is part of
LWLockNames.
- oldserxid, which gets defined in SimpleLruInit(), which itself calls
LWLockRegisterTranche() to define a second event of type LWLock.

So the docs look correct to me on this side.  What I find weird is the
phrasing to define oldserxid.  Instead of that, the current description:
Waiting to I/O on an oldserxid buffer.
I would suggest "waiting *for* I/O"

A small patch is attached.

Thanks,
--
Michael

diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index e138d1ef07..82c015806e 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -1068,7 +1068,7 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
         </row>
         <row>
          <entry><literal>oldserxid</literal></entry>
-         <entry>Waiting to I/O on an oldserxid buffer.</entry>
+         <entry>Waiting for I/O on an oldserxid buffer.</entry>
         </row>
         <row>
          <entry><literal>wal_insert</literal></entry>

signature.asc
Description: PGP signature