On Wed, Jun 13, 2018 at 11:45 PM, Amit Kapila <amit.kapil...@gmail.com> wrote: >> I have tested wal_prefetch at two powerful servers with 24 cores, 3Tb NVME >> RAID 10 storage device and 256Gb of RAM connected using InfiniBand. >> The speed of synchronous replication between two nodes is increased from 56k >> TPS to 60k TPS (on pgbench with scale 1000). > > That's a reasonable improvement.
Somehow I would have expected more. That's only a 7% speedup. I am also surprised that HDD didn't show any improvement. Since HDD's are bad at random I/O, I would have expected prefetching to help more in that case. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
