Log Message:
-----------
Emphasize that immutable and stable functions are not allowed to modify
the database. xfunc.sgml was already pretty definite on the point, but
it doesn't hurt to make it clear here too.
Modified Files:
--------------
pgsql/doc/src/sgml/ref:
create_function.sgml (r1.69 -> r1.70)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/create_function.sgml.diff?r1=1.69&r2=1.70)