Picked up a handy little tip. If you want to move a bunch of data from one Oracle database to another, you can use the exp and imp utilities to dump the data and restore it respectively.
But what if the two databases are different versions? I wanted to do this recently to copy data from an 11g database into an Oracle XE 10g database on my laptop, so I could take it with me. But the imp utility that comes with XE can’t restore the data from the dump produced by the exp utility in 11g.
What to do? Turns out the answer was very easy! All you have to do is use the lower version to do the dump. So in this case, create an entry in the tnsnames.ora on the XE database, pointing to the 11g database, and then use the XE (10g) exp utility to dump the 11g database. This dump can be easily imported into the 10g database.