I wrote:
> * ParameterStatus could be a risk if a function executed during COPY
> tried to change one of the above-mentioned parameters. Since COPY OUT
> doesn't fire triggers, I think user-defined datatype output functions
> would be the only possible candidates for that.
Scratch that --- that thinking is so last-year :-(. COPY OUT from a
SELECT subquery could fire any old function. pg_dump isn't at risk
from that, but other applications would be.
regards, tom lane