What is redo? Let’s look briefly at the redo process. When Oracle blocks (the smallest unit of storage in a database) are changed, including UNDO blocks, Oracle records the changes in vector changes, which are referred to as redo entries or redo records. The changes are written by the server process to the redo log…
Category: Undo
Differences between UNDO and REDO
To clear this question we have this table: UNDO REDO Record of How to undo a change How to reproduce a change Used for Rollback, Read-Consistency Rolling forward DB Changes Stored in Undo segments Redo log files Protect Against Inconsistent reads in multiuser systems Data loss UNDO Undo tablespaces are special tablespaces used solely for…
What is the difference between Rollback and Undo Tablespace? OTN Forum By user user503050
There might be confusion while undo and rollback segment terms are used interchangeably in db world. It is due to the compatibility issue of oracle. Undo Oracle Database must have a method of maintaining information that is used to roll back, or undo, changes to the database. Such information consists of records of the actions…