> On 2 May 2018 at 13:10, Michael Paquier <mich...@paquier.xyz> wrote: > On Wed, May 02, 2018 at 12:22:34PM +0200, Dmitry Dolgov wrote: >> Recently I've heard people complaining that Postgres doesn't expose any >> statistics about how many full page writes happened during some time >> frame. > > pg_waldump --stats?
Yep, pg_waldump is the only option so far, but I thought about something that will directly expose this info. > The bar to add new fields into pgstat structures is usually quite high > depending on the location where those are added. For example not so > long ago there was a patch discussed about adding more fields to > PgStat_StatTabEntry, which has been rejected as pgstat can be a problem > for users with many tables. See here: > https://www.postgresql.org/message-id/1323.1511624064%40sss.pgh.pa.us > > Your patch adds a new field to PgStat_StatDBEntry? Wouldn't you > increase the bottleneck of deployments with many databases? What's > actually your use case? This was discussed mostly in the context of benchmarking and understanding IO for different workloads. I actually never realized that adding a new stats field can have significant impact in those cases when there are too many databases, and yeah, I'm afraid it may be not justified in this context.
