Oracle row change time stamp

Question

Is there a system column - timestamp - in Oracle table to determine when was it changed last time?

I would assume there must be one to let mat views pull changes only ...

Answer 1

Oracle uses System Change Number (SCN). You can access it in a query as ora_rowscn. However, by default it represents the time the entire block was modified not a particular row. If you want row level information, your table must be created with the rowdependencies specifier.

And you are making incorrect assumptions about how materialized views work. Oracle keeps track of changes using tables MLOG$ and $RUPDS.