...

I am curious about the cost of triggers.

The MySQL guys claim that they are very expensive. But if I want to put a
trigger on an "update" for a table so that if changing a "N" to a "Y" in a
status variable it'll go update another table, e.g. sort of a foreign key
constraint since PostGreSQL doesn't have one, what kind of cost is this
for normal operations on that table? (Oh, it will update one single record
in that other table, and the key value has a unique index on it, so that
should not be a problem).

--
Eric Lee Green         eric@linux-hw.com     http://www.linux-hw.com/~eric
     Beware of those who would sell you a 7200RPM Quantum as an
    Enterprise-class hard drive.