Quick Confirmation on Transaction Recovery in Oracle 19c
Ainara, October 01, 2024 - 12:53 pm UTC
Hi Conor,
thanks for your previous insights regarding the scenario in Oracle 19c. I wanted to confirm your explanation: after a database crash, any uncommitted changes made by User B will indeed be lost and not recoverable, as it will be as if the transaction never occurred even redo log has the changes. Could you please confirm this understanding? Thanks again for your help! Best, Ainara
October 04, 2024 - 4:54 am UTC
That is correct.
An uncommitted transaction is invisible to anyone except the session that currently has it active. If that session disappears (eg database crash, or even just session crash) then those changes never happened.
(Behind the scenes we must do work to sort out the mess, but from the observers perspective, it never happened)