On Fri, Jun 7, 2013 at 12:55 PM, Greg Smith <g...@2ndquadrant.com> wrote: > On 6/7/13 12:42 PM, Robert Haas wrote: >> GUCs in terms of units that are meaningful to the user. One could >> have something like io_rate_limit (measured in MB/s), >> io_read_multiplier = 1.0, io_dirty_multiplier = 1.0, and I think that >> would be reasonably clear. > > There's one other way to frame this: > > io_read_limit = 7.8MB/s # Maximum read rate > io_dirty_multiplier = 2.0 # How expensive writes are considered relative to > reads > > That still gives all of the behavior I'd like to preserve, as well as not > changing the default I/O pattern. I don't think it's too complicated to ask > people to grapple with that pair.
That's unsatisfying to me because the io_read_limit is not really an io_read_limit at all. It is some kind of combined limit, but the name doesn't indicate that. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers