2015-11-17 21:00 GMT+01:00 Robert Haas <robertmh...@gmail.com>: > On Tue, Nov 17, 2015 at 2:25 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > > Robert Haas <robertmh...@gmail.com> writes: > >> On Mon, Nov 16, 2015 at 6:05 PM, Andrew Dunstan <and...@dunslane.net> > wrote: > >>> I honestly don't see what's so confusing about it, and if there is any > >>> confusion then surely we could make sure what's happening is well > >>> documented. > > > >> +1. I'm actually kind of wondering if we should just back up and > >> change the way -c works instead, and allow it to be specified more > >> than once. The current behavior is essentially a crock that has only > >> backward compatibility to recommend it, and not having two > >> confusingly-similar options is of some non-trivial value. > > > > Well, it's not *entirely* true that it has only backwards compatibility > > to recommend it: without -c in its current form, there would be no way > > to test multiple-commands-in-one-PQexec cases without hacking up some > > custom test infrastructure. That's not a very strong reason maybe, but > > it's a reason. > > True. We could have a --no-split-commands option for that case, perhaps. > > > And backwards compatibility is usually a strong argument > > around here anyway. > > Yeah, but not - at least in my book - at the expense of being stuck > with a confusing interface forever. > > > I've not been following this thread in any detail, but have we considered > > the approach of allowing multiple -c and saying that each -c is a > separate > > PQexec (or backslash command)? So the semantics of one -c wouldn't > change, > > but commands submitted through multiple -c switches would behave > > relatively unsurprisingly, and we wouldn't need two kinds of switch. > > > > Another issue here is how -1 ought to interact with multiple -c. > > On a code level, I think the issue here is that ACT_SINGLE_QUERY > bypasses a lot of stuff that happens in the ACT_FILE case: directly in > main, there's process_psqlrc(); inside process_file(), there's the > single_txn handling; then inside MainLoop, there's splitting of > commands and cancel handling and various other stuff. In my > imagination, it's like this because originally psql wasn't nearly as > complicated as it is now, and as features got added in various places, > -c gradually diverged. I don't know whether that's really what > happened, but it seems to me that it would be good to bring those > things back together. > > A few years ago there was a proposal to not only allow multiple -c > options, but to allow -c and -f to be intermingled. This seems really > rather useful; I'd like to be able to type psql -c do_this_first -f > script.sql and have that work. But of course it's kind of hard to > figure out how that should behave given the various differences > between -c and -f. I think in the long run we'll be better off > rationalizing the interface; I really doubt how many people, even on > this mailing list, can even enumerate all the differences between -c > and -f. If it's too complicated for hackers to remember, it's > probably not very good for users either. >
This shouldn't be hard. With proposed patch, you can do "-C '\i xxx' -C '\i yyyy'" - that is effectively same like multiple -f and this mix can be really useful }in any order). Regards Pavel > > -- > Robert Haas > EnterpriseDB: http://www.enterprisedb.com > The Enterprise PostgreSQL Company >
