On Thu, Feb 26, 2009 at 3:54 PM, Andrew Dunstan <and...@dunslane.net> wrote: > Robert Haas wrote: >> But the change you're proposing seems like >> it could CONCEIVABLY break a working application that counts on >> PostgreSQL's particular flavor of misbehavior, and therefore it seems >> questionable to put that into a stable branch. The fact that the >> application perhaps should not have been written that way to begin >> with is neither here nor there. We don't want people to be afraid of >> upgrading to the latest point release when we fix, say, a backend >> crash or a data corruption bug. > > Let me reiterate the changes that I propose, and again challenge you to > provide a working counter-example if you believe it will break anything not > currently broken, even cases involving fragments. > > First, I propose that we abandon this mangling, if, and only if, the xml is > in fact a well formed XML document. Since the whole point of the mangling is > to handle situations where the XML is not a well formed document, that seems > fairly straight-forward. If this change were to upset any user, it must be > because they are relying on undisputably incorrect results. > > Second, I propose that, in the remaining cases, where we do mangle the XML, > if the xpath expression does not begin with a '/', instead of prepending it > with '/x/, which can not possibly be correct under any circumstance, we > prepend it with '/x//' which has some possibility of giving correct results. > > IOW, these proposals will expand the number of correct results from the > code, without contributing any new incorrect cases. These changes are *very* > conservative, as is usual when we fix things on stable branches. > > cheers > > andrew
You are right. Nuff said, ...Robert -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers