Re: the case for machine-readable error fields

Tom Lane <tgl@sss.pgh.pa.us> wrote:
> A minimum requirement for such a thing, in my opinion, is that
> *every* occurrence of one of the targeted SQLSTATE codes should be
> able to produce the same auxiliary fields with the same meanings. 
> If you can't define it that way, then you haven't actually made
> things better than looking at the message text.
I would hope that SQLSTATE *categorizes* messages rather than uniquely
identifying them.  If it is being used correctly (as I see it), there
could well be different specific messages within the category
identified by a SQLSTATE for which different identifiers are useful.
I'm not so interested in using this feature, personally; but I am
concerned about how the issue might affect our use of SQLSTATE, about
which I do care.
Many products have a sequence number to identify their messages in
addition to using SQLSTATE to classify them.  That seems pretty
sensible to me.
-Kevin