On Thu, 2020-05-07 at 18:17 -0300, Avinash Kumar wrote: > > The nice thing about separate databases is that it is easy to scale > > horizontally. > > Agreed. But, how about autovacuum ? Workers shift from DB to DB and 500 clusters > means you may have to have a lot of manual vacuuming in place as well.
Just set "autovacuum_max_workers" higher.
No, that wouldn't help. If you just increase autovacuum_max_workers, the total cost limit of autovacuum_vacuum_cost_limit (or vacuum_cost_limit) is shared by so many workers and it further delays autovacuum per each worker. Instead you need to increase autovacuum_vacuum_cost_limit as well when you increase the number of workers. But, if you do that and also increase workers, well, you would easily reach the limitations of the disk. I am not sure it is anywhere advised to have 20 autovacuum_max_workers unless i have a disk with lots of IOPS and with very tiny tables across all the databases.
