On Tue, Oct 20, 2009 at 10:32 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Bruce Momjian <bruce@momjian.us> writes:
>> Tom Lane wrote:
>>> 1. Invent a GUC that has the settings backwards-compatible,
>>> oracle-compatible, throw-error (exact spellings TBD). Factory default,
>>> at least for a few releases, will be throw-error. Make it SUSET so that
>>> unprivileged users can't break things by twiddling it; but it's still
>>> possible for the DBA to set it per-database or per-user.
>
>> I don't see the logic to making the setting SUSET. The user wrote the
>> function; what logic is there to say the resolution rules are not under
>> their control?
>
> That's only sane if you are 100% certain that there could not be a
> security issue arising from the change of behavior. Otherwise someone
> could for instance subvert a security-definer function by running it
> under the setting it wasn't written for. Personally I am not 100%
> certain of that.
>
>> Also, I think to GUC that throws an error or not is a lot safer than one
>> that changes resolution semantics. Changing resolution semantics sounds
>> like the autocommit GUC to me. :-O
>
> Yeah, that's another reason to not allow it to be changed too easily.
>
>> Also, I am not really keen on the "keep it for a few releases"
>
> Well, I'm not necessarily saying we would ever change it. Maybe the
> default could always stay at "error".
>
>> ... maybe just error/no error
>> and using Oracle semantics is the way to go, with 'error' as the
>> default.
>
> I'd personally be entirely happy with that, but people with large
> plpgsql code bases will not be. They're going to want a
> backward-compatible setting so that this doesn't become a show stopper
> for migration to 8.5. Any time you can allow someone to deal with a
> migration issue later instead of right away, it becomes easier for them
> to migrate.
How about warning for release before making the big switch? The text
cast change, while ultimately good, maybe could have been stretched
out for a release or two...it was painful. I do though absolutely
think that it was good in the end to not support a compatibility
option in core.
Didn't we have a long discussion on big compatibility changes with the
consensus that we were to going give a transition release before we
dropped a backwards compatibility bomb? I can't help feeling that we
are about to jump off into the abyss...
merlin
