On Thu, Jan 23, 2014 at 2:06 AM, Peter Eisentraut <peter_e@gmx.net> wrote:
I'm not totally happy with the choice of ":" as the mapping separator, because that would always require escaping on Windows. We could make it analogous to the path handling and make ";" the separator on Windows. Then again, this is not a path, so maybe it should look like one. We pick something else altogether, like "=".
The option name "--tablespace" isn't very clear. It ought to be something like "--tablespace-mapping".
This design choice I made about -T (--tablespace) and colon as
separator was copied from pg_barman, which is the way I back up my
clusters at the moment. Renaming the option to --tablespace-mapping and
changing the syntax to something like "=" is totally fine by me.
I changed the directory separator from ":" to "=" but made it
configurable in the code.
I don't think we should require the new directory to be an absolute path. It should be relative to the current directory, just like the -D option does it.
Accepting a relative path should be fine, I made a failed attempt using
realpath(3) initially but I guess checking for [0] != '/' and
prepending getcwd(3) would suffice.
Relative paths are now accepted. This code will probably not work on
windows though. I tried setting up Windows 8 with the git version of
postgres but was unsuccessful, so I can't really test any of this.
Help on this subject (Windows) would be much appreciated.
Somehow, I had the subconscious assumption that this feature would do prefix matching on the directories, not only complete string matching. So if I had tablespaces in /mnt/data1, /mnt/data2, /mnt/data3, I could map them all with -T /mnt:mnt and be done. Not sure if that is useful to many, but it's worth a thought.
I like that a lot, but I'm afraid the code would have to get a bit more
complex to add that functionality. It would be an easier rewrite if we
added a hint character, something like -T '/mnt/*:mnt'.
This is not implemented as suggested by Peter in his previous comment.
-T /mnt:mnt now relocates all tablespaces under /mnt to the relative
I've updated error messages according to the style guide.
We need to think about how to handle this on platforms without symlinks. I don't like just printing an error message and moving on. It should be either pass or fail or an option to choose between them.
I hope someone with experience with those kind of systems can come up
with suggestions on how to solve that. I only run postgres on Linux.
I would still love some input on this.
Please put the options in the getopt handling in alphabetical order. It's not very alphabetical now, but between D and F is probably not the best place. ;-)
