"Christoph Jaeger" <christoph(dot)jaeger(at)dhl(dot)com> writes:
> PostgreSQL version (example: PostgreSQL-7.3.4): postgresql 7.1.3
7.1.3 is ancient history, and no it doesn't have defenses against you
changing a column definition that a foreign key linkage refers to.
I'd recommend updating to 7.3.4.
> The table pg_trigger shows three rows, which seem to point to this no
> longer valid constraint, but I do not think it is a good idea to fiddle
> with this unless one really knows how this all works together.
In 7.1, drop the triggers and you're done. AFAIR this would also be
necessary in 7.2. In 7.3 you could have just dropped the columns you
wanted to drop, and not had all these problems.
regards, tom lane