Export to the compressed file
/etc/mknod my_own_pipe p
gzip -c -9 < my_own_pipe > mydump.gz &
exp username/password ...... file=my_own_pipe
rm -f my_own_pipe
Import from the compressed file:
/etc/mknod my_own_pipe p
gunzip -c mydump.gz > my_own_pipe &
imp username/password ....... file=my_own_pipe
rm -f my_own_pipe