On Thu, Sep 28, 2017 at 08:02:44AM -0700, kbrannen@xxxxxxxxxx wrote: > With Pg10.0 coming, I have a question about pg_stat_tmp and upgrades that I'm hoping I can get some advice on. > > Historically, we've created a tmpfs "disk" and mounted it on $PGDATA/pg_stat_tmp and then started Pg. For > most situations, this works well. However, we have one situation where it doesn't. Therefore, we've decided > to put pg_stat_tmp outside of $PGDATA. > > OTOH, it occurs to me that when we run pg_upgrade, we're going to have 2 Pg's running at the same time. So > my concern is that if both new and old have "stats_temp_directory = '/db/pg_stat_tmp'" in their > postgresql.conf, are there going to be conflicts and "bad things" happen? Or is there some sort of > versioning within that area that will keep stuff separate and we'll be OK? > > I'm concerned because I don't see anything like versioning when I look in the "dir", so if both of them try > to create a "global.stat" then it seems like "bad things" could happen. > > OTOH, it's only stats and only an upgrade, so would it be better to make sure that the new version doesn't > use that (that config isn't set so it uses the dir in PGDATA) and then change it over once the upgrade is > done or what? > > I could see where the upgrade process wouldn't do anything with stats while the 2 servers are running (but > only after the upgrade is done) so this might not matter. I will also say that I don't see anything like > this mentioned in the 10.0 docs for pg_upgrade. > > I don't think it matters, but we'll be going from 9.5.1 to 10.0. pg_upgrade never runs the old and new servers at the same time. I am not sure if that would be OK, but I have never heard of problems related to this. I am afraid you will just need to test it. -- Bruce Momjian <bruce@xxxxxxxxxx> http://momjian.us EnterpriseDB http://enterprisedb.com + As you are, so once was I. As I am, so you will be. + + Ancient Roman grave inscription + -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
