Before implementing Don's tips on backing up the database, I tried to verify that the dumped database would reload properly. Hence I did first
pg_dump my_database > my_database_bkup.
Next I created a new database my_database_test and did
psql -d my_database_test -f
Unfortunately I got a number of errors on the reload. By the way I did all of the above as nsadmin. Some of the errors seem to be due to the order in which the orginal dump took place. Some create table commands required functions (eg sysdate) to be already defined. Others I am not sure what produced the errors.
Are there some hints that I am missing to do the dump and reload properly?