Re: double insert on inherited table with where constraint based on sequence - Mailing list pgsql-bugs

"Andrew Hammond" <andrew.george.hammond@gmail.com> writes:
> Rules:
>     t2_part AS
>     ON INSERT TO t2
>    WHERE new.id > 10 DO INSTEAD  INSERT INTO t2_child (id, name)
>   VALUES (new.id, new.name)

"new.id" is replaced by "nextval('t2_id_seq'::regclass)" each time it
appears ... which will be four separate times, viz the two evaluations
of the WHERE clause and the two VALUES clauses.

Basically, volatile functions and rules do not mix.  Consider using
a trigger on t2 instead to redirect the insert somewhere else.

            regards, tom lane