uncommited redo changes
stee1ratDec 18 2012 — edited Dec 18 2012Hello, All!
I have another stupid question to ask :)
As I understand a transaction mechanism in oracle: all uncommitted changes generates a redo records that is stored in log buffer. After session commits all this changes syncs with redo log file, causing committing session to wait for a log file sync event. As long as log buffer is very small it's always dumps to redo log file in background (depending on it's filling or every 3 secs).
So i wonder what happens when the session not commits it's changes, but invokes rollback. How database knows that it shouldn't apply those changes from redo in case of instance recovery?
Edited by: stee1rat on Dec 18, 2012 10:33 AM