ORA-19910: can not change recovery target incarnation in control file

If you are trying to resolve ORA-19909 on your physical standby database which is out of sync with primary because of ORA-19909, and you face ORA-19910, the probably cause is that redo apply process is still active. This was exactly the case with me when I tried to reset the incarnation number of my physical primary database. In the following you can see the exact command and error message returned.

Error ORA-235 occurred during an un-locked control file transaction

Error ORA-235 occurred during an un-locked control file transaction.  This error can be ignored.  The control file transaction will be retried. RFS[2]: Opened log for thread 2 sequence 40781 dbid 2440526278 branch 1089779374 RFS[3]: Opened log for thread 1 sequence 40695 dbid 2440526278 branch 1089779374 RFS[4]: Opened log for thread 1 sequence 40693 dbid 2440526278 branch 1089779374 RFS[1]: Opened log for thread 2 sequence 40779 dbid 2440526278 branch 1089779374 Tue Mar 21 04:11:38 2023 Archived Log entry 66837 added for thread 2 sequence 40781 rlc 1089779374 ID 0x0 dest 2: Tue Mar 21 04:11:40 2023 Archived Log entry 66838 added for thread 1 sequence 40693 rlc 1089779374 ID 0x0 dest 2: Tue Mar 21 04:11:40 2023 Archived Log entry 66840 added for thread 1 sequence 40695 rlc 1089779374 ID 0x0 dest 2: Tue Mar 21 04:11:43 2023

Read by Other Session - Oracle Wait Event

Prior to 10.1 version, this wait event was part of Buffer Busy Wait, however, after 10.1 this wait event was separated from buffer busy wait and is now visible in AWR reports. This wait event is reported if multiple sessions are waiting for the same data block to be read from the disk into the buffer cache. This could be alarming if this wait event is reported as one of the top wait events in the AWR reports. There could be different causes of this wait event to be at the top. In this article I will discuss how we can troubleshoot this wait event.