Re: Why doesn't `RAISE EXCEPTION` provide error context?

2015-04-02 9:13 GMT+02:00 David G. Johnston <david(dot)g(dot)johnston(at)gmail(dot)com>:

> Adding "raw" content present on Nabble that gets filtered by the mailing
> list.
>
> On Wednesday, April 1, 2015, Taytay <taylor(at)youneedabudget(dot)com> wrote:
>
>> We make heavy use of `GET STACKED DIAGNOSTICS` to determine where errors
>> happened.
>> However, I am trying to use RAISE EXCEPTION to report errors, and have
>> discovered that RAISE is specifically prevented from adding to the error
>> context:
>
>
> ----
> static void
> plpgsql_exec_error_callback(void *arg)
> {
> PLpgSQL_execstate *estate = (PLpgSQL_execstate *) arg;
>
> /* if we are doing RAISE, don't report its location */
> if (estate->err_text == raise_skip_msg)
> return;
> ----
>

We talked more time about a change of this behave - the discus finished
without end

http://www.postgresql.org/message-id/CAFj8pRDFHqv7cKXP-K+uBzW6627HytT7bct4ZxDBseLXc1Rcgg@mail.gmail.com

I am thinking, so current design is too simple and should be changed, and
if will be a agreement I can add this patch to next commitfest.

Regards

Pavel

>
>
>>
>> So that means that this doesn't work:
>>
>>
>>
> RAISE EXCEPTION 'This exception will not get a stack trace';
>
> EXCEPTION WHEN others THEN
>
> -- If the exception we're catching is one that Postgres threw,
> -- like a divide by zero error, then this will get the full
> -- stack trace of the place where the exception was thrown.
> -- However, since we are catching an exception we raised manually
> -- using RAISE EXCEPTION, there is no context/stack trace!
> GET STACKED DIAGNOSTICS v_error_stack = PG_EXCEPTION_CONTEXT;
>
>
>> I've posted more details here:
>>
>> http://dba.stackexchange.com/questions/96743/postgres-how-to-get-stack-trace-for-a-manually-raised-exception
>>
>> That context would be awfully useful for us, even for manually generated
>> exceptions.
>> Can anyone shed some light on A) why this is, and B) if it's still
>> desired,
>> and C) if so, are there any workarounds? Is there an exception I can trick
>> Postgres into throwing that will include my user-generated string?
>>
>> Many thanks for any help you can offer.
>>
>>
>
>