By default, pg_dump uses COPY to restore its data when we use
the plain text form, however, it's not the case when we use
the customer format, e.g.
pg_dump -Fc mydb > mydb.out
the documenation of pg_restore address
su-2.05$ time psql urldb<jurloldmail.out
You are now connected as new user jliang.
CREATE
real 0m0.662s
user 0m0.045s
sys 0m0.015s
su-2.05$ time pg_restore -cvt jurloldmail -d urldb urldb.out.020810
pg_restore: connecting to database for restore
pg_restore: dropping TABLE jurloldmail
pg_restore: connecting to database urldb as user jliang
pg_restore: creating TABLE jurloldmail
pg_restore: restoring data for table jurloldmail
real 0m6.880s
user 0m0.296s
sys 0m0.028s