On 19.10.2018 0:54, Peter Geoghegan wrote:
> I would welcome any theories as to what could be the problem here. I'm
> think that this is fixable, since the picture for the patch is very
> positive, provided you only focus on bgwriter/checkpoint activity and
> on-disk sizes. It seems likely that there is a very specific gap in my
> understanding of how the patch affects buffer cleaning.
I have same problem with background heap & index cleaner (based on your
patch). In this case the bottleneck is WAL-record which I need to write
for each cleaned block and locks which are held during the WAL-record
writing process.
Maybe you will do a test without writing any data to disk?
--
Andrey Lepikhov
Postgres Professional
https://postgrespro.com
The Russian Postgres Company