create script to update database

I have a large database, which contains records for assets, including cars, corporations, liens, property, etc. Think, a few million records. A new version of that DB comes to me about every 3 months with updated information. The fields and field definitions tend to be the same all the time. But the information is new in terms of records that change and so on. I need a script that will: 1. Deprecate all the information that we do not need (about 50% of all information, in terms of entire tables that just need to be ignored, and many fields that need to be ignored as well) 2. Backup then dump the current version 3. Upload the latest version 4. Restore the backup if something goes wrong... The idea? Simple. Every time I get the new version of the DB, I upload the files as I receive them (.TXT files) and run the script, which replaces old info with new info and I continue working as usual. If for any reason that does not work, I run the "roll back script" which will prompt for latest backup, run it, THANK YOU, and keep on working...