I ran a couple of tests for pg_upgrade with 100k tables (created using the script here [0]) in order to demonstrate the potential benefits of this patch.
pg_upgrade --sync-method fsync
real 5m50.072s
user 0m10.606s
sys 0m40.298s
pg_upgrade --sync-method syncfs
real 3m44.096s
user 0m8.906s
sys 0m26.398s
pg_upgrade --no-sync
real 3m27.697s
user 0m9.056s
sys 0m26.605s
[0] https://postgr.es/m/3612876.1689443232%40sss.pgh.pa.us
--
Nathan Bossart
Amazon Web Services: https://aws.amazon.com
