On Thu, Feb 03, 2022 at 01:05:50PM -0500, Robert Haas wrote: > On Thu, Dec 9, 2021 at 8:56 PM Andres Freund <and...@anarazel.de> wrote: > > I think we should move *away* from single user mode, rather than the > > opposite. It's a substantial code burden and it's hard to use. > > Yes. This thread seems to be largely devoted to the topic of making > single-user vacuum work better, but I don't see anyone asking the > question "why do we have a message that tells people to vacuum in > single user mode in the first place?". It's basically bad advice,
> The correct thing to do would be to remove > the hint as bad advice that we never should have offered in the first > place. And so here. We should not try to make vacuum in single > user-mode work better or differently, or at least that shouldn't be > our primary objective. We should just stop telling people to do it. We > should probably add messages and documentation *discouraging* the use > of single user mode for recovering from wraparound trouble, exactly > the opposite of what we do now. There's nothing we can do in > single-user mode that we can't do equally well in multi-user mode. If > people try to fix wraparound problems in multi-user mode, they still > have read-only access to their database, they can use parallelism, > they can use command line utilities like vacuumdb, and they can use > psql which has line editing and allows remote access and is a way > nicer user experience than running postgres --single. We need a really > compelling reason to tell people to give up all those advantages, and > there is no such reason. It makes just as much sense as telling people > to deal with wraparound problems by angering a live anaconda. By chance, I came across this prior thread which advocated the same thing in a initially (rather than indirectly as in this year's thread). https://www.postgresql.org/message-id/flat/CAMT0RQTmRj_Egtmre6fbiMA9E2hM3BsLULiV8W00stwa3URvzA%40mail.gmail.com |We should stop telling users to "vacuum that database in single-user mode"
