My Understanding of Cumulative level 1 - backups up all the modified block since the last level 0 backups plus also the duplicate level 1 incremental copies , if we ran any level 1 incremental before executing cumulative level 1 backup.
having said that I came across the below documentation in Oracle .
Assume a case in which REDUNDANCY is 1. You run a level 0 database backup at noon Monday, a level 1 cumulative backup at noon on Tuesday and Wednesday, and a level 0 backup at noon on Thursday. Immediately after each daily backup you run a DELETE OBSOLETE. The Wednesday DELETE command does not remove the Tuesday level 1 backup because this backup is not redundant: the Tuesday level 1 backup could be used to recover the Monday level 0 backup to a time between noon on Tuesday and noon on Wednesday. However, the DELETEcommand on Thursday removes the previous level 0 and level 1 backups.
Can anyone explain me detail as why Tue level 1 backup needed ? when we have Wed backup piece which has TUE backup ( i,e which has Mon backup)
so to recover the database I think only one backup piece that is Wednesday needed .
please correct me if I am wrong . sorry for my bad English if u find any grammatical mistake
Also put me like What TUE level 1 cumulative backup piece will contain
for example Monday level 0 data Plus Tue Morning data plus Tue noon data
Thanks
Thanks