Hi all,

I trying to get clear on my mind what is the difference or relation between the redo log files and the rollback segments.

The redo log file definition said: disk resources that store data changes made by users on Oracle.
The rollback segments is: stores data changes for transactions to provide read consistency and transaction concurency, stores old data values when a process is making changes.

So, the redo logs is for storing the new value of data, and the rollback the old one.

Phsysicaly, the redo logs have members with 2 files each that oracle recommends to put on different HD, and the rollback segments the file or files set up for the related tablespace.

1. Until here is no relation, rigth?
2. The redo log must be much more important because there are 2 files containing identical copy of another's data, why the rollback are less important?
3. The new value of data(redo log information) are written to database when commit or checkpoint occurs?


putting this down already cleared my mind a little, did I miss something?