On Wed, Jan 15, 2014 at 7:54 AM, Magnus Hagander <mag...@hagander.net> wrote: > On Wed, Jan 15, 2014 at 3:20 AM, Simon Riggs <si...@2ndquadrant.com> wrote: >> We've discussed previously the negative impact of large bulk >> operations, especially wrt WAL writes. Patch here allows maintenance >> operations to have their WAL generation slowed down as a replication >> lag prevention feature. >> >> I believe there was originally intended to be some work on I/O rate >> limiting, but that hasn't happened and is in some ways orthogonal to >> this patch and we will likely eventually want both. >> >> Single new parameter works very similarly to vacuum_cost_delay >> >> wal_rate_limit_delay = Xms > > > Seems like a really bad name if we are only slowing down some commands - > that seems to indicate we're slowing down all of them. I think it should be > something that indicates that it only affects the maintenance commands.
And why should it only affect the maintenance commands anyway, and who decides what's a maintenance command? I thought Heroku suggested something like this previously, and their use case was something along the lines of "we need to slow the system down enough to do a backup so we can delete some stuff before the disk fills". For that, it seems likely to me that you would just want to slow everything down. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
