Re: What *really* happens at ALTER TBSP END BKP ?

Thank you, that's a very helpful illustration.

The site where I work has only recently switched to hot backups and the questions I and colleagues have needed answering really don't appear in the manuals. For years I'd done ad-hoc hot backups and actually had the misconception that the datafiles were untouched whilst in hot backup. (Another debate had been whether you needed to use OCOPY (on NT) to copy the files out during hot backup. The conclusion reached is that as long as your copy method can actually copy the file without error then it's okay to use it.)

The definitions I used were simply taken from Oracle's glossary - "Oracle8i Generic Documentation Master Glossary". The 8i one was:
Checkpoint = A pointer indicating that all changes prior to the SCN specified by a redo record have been written to the datafiles by DBWn. ...

The 9i Release 2 is using:
Checkpoint = A data structure that defines an SCN in the redo thread of a database. Checkpoints are recorded in the control file and each datafile header, and are a crucial element of recovery.

So a checkpoint has changed from being a pointer to being the actual data structure. If anything the new definition is woollier since it's not telling you what happens at a checkpoint.

I would say there was definitely scope for Oracle to expand on their hot backup topic.

Daniel. Received on Sun Jul 06 2003 - 17:12:32 CDT