Oracle Database Discussions

Hi.

I was performing backup and recovery using RMAN and noticed that the results varied depending on the archive log creation timing. However, I am unsure why this happens, so I am asking for clarification.

Backup Command

# fullbackup
run {
allocate channel c1 type disk;
backup database format '/home/oracle/rman/level0_%T_%U';
}

# incremental 1
run {
allocate channel c1 type disk;
backup INCREMENTAL Level 1 database
format '/home/oracle/rman/level1cum_%T_%U';
}

# incremental 2
run {
allocate channel c1 type disk;
backup INCREMENTAL Level 1 database 
format '/home/oracle/rman/level2_%T_%U';
}

I generated archive logs using ALTER SYSTEM SWITCH LOGFILE and conducted the test in the following sequence:

1. Full backup
2. Data insertion
3. First incremental backup
4. Data insertion
5. Second incremental backup
6. Multiple archive log generations
7. Deletion of data and archive logs
8. Restore and recover when first incremental backup

When following this sequence, I encountered the following error

In the second test, I changed the sequence as follows:

1. Full backup
2. Data insertion
3. Multiple archive log generations
4. First incremental backup
5. Data insertion
6. Second incremental backup
7. Deletion of data and archive logs
8. Restore and recover when first incremental backup

With this approach, the test was successful, and I was able to recover to the desired first incremental backup point.

I am curious about why the results differ based on the timing of archive log generation. Could you please explain this behavior? Thank you.