If you are on 8i and the table has a snapshot log then the TAB$.SPARE3 column has the SCN of the first DML to fire the internalized trigger for the snapshot log since the last snapshot refresh operation. That is not necessarily the last DML operation, but it may help. Otherwise, so far as I am aware, you would have to dig into the log files to find the last DML.

I know this is not a performance question, but it is one which I've often thought about and now a colleague is asking if it's possible to identify when a table was last modified? The DBA's in his office believe it cannot be done. He thinks the table has been rolled back, but he needs to prove it. Have you come across this situation before and do you know if it's possible. I'm sure there must be away to track block changes?