I had to do this with an Access database not long ago. A person was given a copy of the database to do a special study and deleted all of the records that they didn't need for their whatever. Unfortunately they were given a copy of the front-end that connected to the live database, so records went bye-bye.
Fortunately we have pretty good backups and recovery, though a bit of work, wasn't too bad. According to my notes, the user wiped 12,000 records from one table, 20,000 from another.
Such fun! I love what I do for a living!
Knowledge is of two kinds. We know a subject ourselves or we know where we can find information upon it. --Samuel Johnson