On 2018-Oct-03, Michael Paquier wrote: > On Tue, Oct 02, 2018 at 10:35:02PM -0300, Alvaro Herrera wrote: > > I'm not clear what interface are you proposing. Maybe they would just > > use the clone-or-fail mode, and note whether it fails? If that's not > > it, please explain. > > Okay. What I am proposing is to not have any kind of automatic mode to > keep the code simple, with a new option called --transfer-mode, able to > do three things: > - "link", which is the equivalent of the existing --link. > - "copy", the default and the current behavior, which copies files. > - "clone", the new mode proposed in this thread.
I see. Peter is proposing to have a fourth mode, essentially --transfer-mode=clone-or-copy. Thinking about a generic tool that wraps pg_upgrade (say, Debian's wrapper for it) this makes sense: just use the fastest non-destructive mode available. Which ones are available depends on what the underlying filesystem is, so it's not up to the tool's writer to decide which to use ahead of time. -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
