what happens in Oracle hot backup?
568189Jan 12 2008 — edited Jan 13 2008i have some few question creeping up my mind on hot backup.
1. alter tablespace <name> begin backup
a tablespace checkpoint occurs and all modified data for the tablespace are logged into respective datafile by DBWr.
SCN gets frozen at this point.
2.i do a cp of my datafile to backup location
My question:
i know that oracle at this point instead of logging a redo vector it will log the whole datablock when the change is made even for a particular transaction.
suppose i make change to the same block (which is already logged in the redo_buffer) what will happen?
3 when i end the backup
what will happen. How will the SCN move which was freezed until now