Monitor Tablespace Autoextend Operations

Dear All,

on our System all tablespaces are auto extend off. Storage increase are handled manual.

Now we need to turn Auto-extend on for some datafiles in some tablespaces, and the question how to monitor this operation. is there a view where I could find info about the increase in a datafile, like the time when the extension is happened.

Why we need that, because we have to save this info and report it to mangers as a chart. "how the storage growth" "when the tbs was much increased" and so on.

And other question:

how the thresholds occur when auto-extend is on?