Re: patch for 9.2: enhanced errors

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Pavel Stehule <pavel.stehule@gmail.com>
Cc: Steve Singer <ssinger_pg@sympatico.ca>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2011-07-18T18:56:44Z
Lists: pgsql-hackers
Pavel Stehule <pavel.stehule@gmail.com> writes:
> There is only one issue, that should be solved first. I introduced non
> standard diagnostics field "column_names", because there is not
> possible get "column_name" value for check constraints now.  A correct
> implementation of COLUMN_NAME field needs a explicit relation between
> pg_constraint and pg_attribute - maybe implemented as new column to
> pg_constraint. Do you agree?

No, I don't.  You're adding complication to solve a problem that doesn't
need to be solved.  The standard says to return the name of the
constraint for a constraint-violation failure.  It does not say anything
about naming the associated column(s).  COLUMN_NAME is only supposed to
be defined for certain kinds of errors, and this isn't one of them.

			regards, tom lane