Обсуждение: [HACKERS] Documentation about pg_stat_bgwriter
Hi. While I read the documentation I found the following description about some columns in pg_stat_bgwriter. https://www.postgresql.org/docs/devel/static/monitoring-stats.html#pg-stat-bgwriter-view This table shows cluster-global values, not per-backend values. > maxwritten_clean: > Number of times the background writer stopped a cleaning scan > because it had written too many buffers > buffers_backend: > Number of buffers written directly by a backend > buffers_backend_fsync: > Number of times a backend had to execute its own fsync call > (normally the background writer handles those even when the > backend does its own write) Since the values are the summary in a cluster, the 'a backend's in the last two seems wrong *to me*. I suppose the 'a backend' should be just 'backends' or 'backends other than the background writer' (This seems a bit verbose.). regards, -- Kyotaro Horiguchi NTT Open Source Software Centerhas
On 5/10/17 04:38, Kyotaro HORIGUCHI wrote: > Hi. While I read the documentation I found the following > description about some columns in pg_stat_bgwriter. > > https://www.postgresql.org/docs/devel/static/monitoring-stats.html#pg-stat-bgwriter-view > > This table shows cluster-global values, not per-backend values. > >> maxwritten_clean: >> Number of times the background writer stopped a cleaning scan >> because it had written too many buffers >> buffers_backend: >> Number of buffers written directly by a backend >> buffers_backend_fsync: >> Number of times a backend had to execute its own fsync call >> (normally the background writer handles those even when the >> backend does its own write) > Since the values are the summary in a cluster, the 'a backend's > in the last two seems wrong *to me*. I suppose the 'a backend' > should be just 'backends' or 'backends other than the background > writer' (This seems a bit verbose.). The text looks correct to me as it currently stands. Your alternative phrasings are also correct. But there is no need to change this, I think. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
Hello, thank you for the reply. At Thu, 18 May 2017 20:48:44 -0400, Peter Eisentraut <peter.eisentraut@2ndquadrant.com> wrote in <343d4cdb-e25d-867d-2830-6502eca4df5c@2ndquadrant.com> > On 5/10/17 04:38, Kyotaro HORIGUCHI wrote: > > Hi. While I read the documentation I found the following > > description about some columns in pg_stat_bgwriter. > > > > https://www.postgresql.org/docs/devel/static/monitoring-stats.html#pg-stat-bgwriter-view > > > > This table shows cluster-global values, not per-backend values. > > > >> maxwritten_clean: > >> Number of times the background writer stopped a cleaning scan > >> because it had written too many buffers > >> buffers_backend: > >> Number of buffers written directly by a backend > >> buffers_backend_fsync: > >> Number of times a backend had to execute its own fsync call > >> (normally the background writer handles those even when the > >> backend does its own write) > > Since the values are the summary in a cluster, the 'a backend's > > in the last two seems wrong *to me*. I suppose the 'a backend' > > should be just 'backends' or 'backends other than the background > > writer' (This seems a bit verbose.). > > The text looks correct to me as it currently stands. Your alternative > phrasings are also correct. But there is no need to change this, I think. It's enough for me to know that it's not a kind of typo. Thanks. regards, -- Kyotaro Horiguchi NTT Open Source Software Center