Flashback, Recycle Bin & Archived logs
578585Aug 6 2007 — edited Aug 6 2007I am a bit confused about Recycle Bin and Flashback techniques. I have got a couple of observations I would like to know your opinion about:
1)After dropping a table, even if a database is in NOARCHIVELOG and my last backup is dated some days earlier than the drop, this does not necessarily means the table is lost since as of my knowledge we can attempt to retrieve the table from the Recycle Bin. The data blocks associated with the table might be still intact in the space now marked as free space and visible in the DBA_FREE_SPACE view.
The recycle bin, a logical structure within each tablespace might be a last resource to recover a dropped table as long as such table is present in the view RECYCLEBIN.
The object can be retrieved by :
flashback table <tablename> to before drop;
This needs not to be confused with flashback queries that retrieve data or objects from the undo data which is a completely different source than the recycle bin memory structure.
There is a basic difference from the 2 following statements:
flashback table <tablename> to before drop; (pointing to recycle bin)
flashback table <tablename> to timestamp systimestamp - interval '120' minute; (pointing to undo)
So if what I said so far is correct I am seing some confusion around this subject and would really appreciate if you guys suggest a clearer picture.
2) Flashback Technology doesn't necessarily need the DB to be in ARCHIVELOG.
I mean can I flashback tables while being in NOARCHIVELOG (for a limited time of course) ? Again, I am saying this because Flashback does not need archived logs but only undo data to my knowledge. This is what I understood.
Your inputs are greatly appreciated.
enrico