On Wed, Aug 26, 2020 at 9:42 AM Sait Talha Nisanci <sait.nisa...@microsoft.com> wrote: > I have tried combination of SSD, HDD, full_page_writes = on/off and > max_io_concurrency = 10/50, the recovery times are as follows (in seconds): > > No prefetch | Default prefetch > values | Default + max_io_concurrency = 50 > SSD, full_page_writes = on 852 301 > 197 > SSD, full_page_writes = off 1642 1359 > 1391 > HDD, full_page_writes = on 6027 6345 > 6390 > HDD, full_page_writes = off 738 275 > 192
The regression on HDD with full_page_writes=on is interesting. I don't know why that should happen, and I wonder if there is anything that can be done to mitigate it. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
