On Mon, Jun 6, 2016 at 3:30 AM, Michael Paquier
<michael.paquier@gmail.com> wrote:
> On Sun, Jun 5, 2016 at 11:16 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Michael Paquier <michael.paquier@gmail.com> writes:
>>> Still, on back branches I think that it would be a good idea to have a
>>> better error message for the ones that already throw an error, like
>>> "trigger with OID %u does not exist". Switching from elog to ereport
>>> would be a good idea, but wouldn't it be a problem to change what is
>>> user-visible?
>>
>> If we're going to touch this behavior in the back branches, I would
>> vote for changing it the same as we do in HEAD. I do not think that
>> making a user-visible behavior change in a minor release and then a
>> different change in the next major is good strategy.
>
> So, I have finished with the patch attached that changes all the
> *def() functions to return NULL when an object does not exist. Some
> callers of the index and constraint definitions still expect a cache
> lookup error if the object does not exist, and this patch is careful
> about that. I think that it would be nice to get that in 9.6, but I
> won't fight hard for it either. So I am parking it for now in the
> upcoming CF.
>
>> But, given the relative shortage of complaints from the field, I'd
>> be more inclined to just do nothing in back branches. There might
>> be people out there with code depending on the current behavior,
>> and they'd be annoyed if we change it in a minor release.
>
> Sure. That's the safest position. Thinking about the existing behavior
> for some of the index and constraint callers, even just changing the
> error message does not bring much as some of them really expect to
> fail with a cache lookup error.
Committed with minor kibitizing: you don't need an "else" after a
statement that transfers control out of the function. Shouldn't
pg_get_function_arguments, pg_get_function_identity_arguments,
pg_get_function_result, and pg_get_function_arg_default get the same
treatment?
--
Robert Haas
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