salah jubeh <s_jubeh(at)yahoo(dot)com> writes:
> Is this a bug ?
No, it's a documented, operating-as-designed behavior. Rules are macros
and therefore have all the usual multiple-evaluation-of-arguments
hazards.
If you just want to propagate data from one table to another, a trigger
is often a better choice, or at least one with fewer surprises.
regards, tom lane