Hi,
I think another way is to take advantage of each database export/import features and use the recommended format for them. For example, for MySQL you can use LOAD DATE INFILE and this statement reads rows from a text file into a table at a very high speed. The file name must be given as a literal string. I have a range of import tools available at http://opencart.hostjars.com/. You can import from CSV or XML, sometimes also straight from a DB.
Regards,
Ronnie