Re: [HACKERS] pg_stat_wal_write statistics view

On Tue, Dec 12, 2017 at 4:18 AM, Haribabu Kommi
 wrote:
> I ran the pgbench performance after removing stats collector usage and
> moving
> the stats into shared memory. I find it that this stats addition doesn't
> have any
> overhead while collecting the stats. I ran these tests on a small machine,
> these may
> need to be retested on an high end machine to confirm that there is no
> impact.
>
> Threads Clients HEAD PATCH Diff
> 1 1 88.72981533 88.527789 -0.23%
> 2 2 88.17999           88.823842 0.73%
> 4 4 169.430813 167.897937 -0.90%
> 8 8 311.790313 315.6659117 1.24%
> 16 16 558.6014777 562.5883583 0.71%
> 32 32 874.0996587 899.855634 2.95%
>
> Attached is the updated patch accordingly to use the shared memory stats.

I think the concerns have more to do with systems that have a huge
number of tables.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company