Markus Bertheau <twanger@bluetwanger.de> writes:
> how would I find out details about for example what constraint was
> violated by an insert statement?
You can't, at the moment, except by parsing the text message.
The "error fields" facility in the FE/BE protocol could be extended
in that direction, and I think there's already been some discussion
about it; but no one has stepped up with a concrete proposal, much
less volunteered to do the work ...
regards, tom lane