Oracle Database Discussions

I'm curious about the backup lines used in your RMAN script.
You may want to post your full DB version.
It's been awhile since I managed backups. All these are from my flawed memory when I was on 11.2.0.3
Every week, Oracle would do something that would cause (what seemed like) every row in every table to be rearranged. (We were licensed for Advanced Compression so full backups weren't a problem)
/*+ APPEND */ steps had a habit of invalidating tablespoons. These had to be "full backup" "manually" in order to ensure my backups worked as expected. (I had a script to level 0 incremental backup specific tablespaces)

First, it would help if you actually posted the backup scripts, as copied/pasted text, formatted and code-blocked.
Beyond that I'd point out that cumulative (not **ac**cumulative) backups have all the changes since the last full/incremental 0 backup. So I'd expect each successive one to get larger than the previous. If you want the daily incremental backup to remain small, then you would take an incremental differential backup. The trade-off is that the differentials will take less disk space, but require more pieces to be applied in the event of a recovery.

Is that one line the entire script? In any event, in addition to any script, we'd need to see the basic settings - an rman 'show all' while connected to the target database.

I just copy one line of syntax incremental accumulative backup
This is like pulling teeth. If we want to know how a particular backup operation is behaving, we need to see the entire script, as well as the configuration settings. A runtime log of the backup could be helpful as well.

but i notice that every two days system is backup size same as full backup
Perhaps every two days you have some operation that touches most of the blocks, thus causing nearly a full backup. And again, a cumulative backup gets all of the blocks that have been changed since the last full/incr 0 backup. So I'd expect each successive cumulative backup to be larger than the previous, until you take a new full/incr 0 backup.

Day 1 - Incremental 0 (full) backup.
Day 2 - since yesterday, only block id= 1 has changed so the cumulative backup gets only that block.
Day 3 - since yesterday, only block id = 2 has changed, but we are taking a cumulative backup, so we get blocks 1 and 2.
Day 4 - since yesterday, only block id = 3 has changed, but we are taking a cumulative backup, so we get blocks 1 and 2 and 3.

etc, etc, etc.

Depends on how many blocks were touched.
But I see a very important problem with your script. First, even your 'backup' command itself is much more complex than what you first indicated, when you tried to show 'just' the backup command.
More importantly, you are manually creating your own directories in the FRA, then specifying those specific directories in your backups. Why are you doing this? This bypasses the bookeeping of the FRA space, so that your FRA will always have less actual disk space than it thinks it has. You should simply configure your FRA size and location (one time setup in the DB), then let everything default to the location that oracle wants to use. The whole idea of the FRA is that oracle - not the DBA - manages everything in it.
You are also writing your rman log files into the same directory as used by the FRA, but this is NOT an FRA-managed file.

i dont get your idea.

I'm afraid you will have to be a bit more explicit about what it is you do not understand.

What's the result of following query?

select trunc(bs_completion_time) completion_date, file_type, bs_incr_type, round(sum(bytes)/1048576) mb
from V$BACKUP_FILES
where bs_completion_time > trunc(sysdate)-7
group by trunc(bs_completion_time), file_type, bs_incr_type
order by trunc(bs_completion_time) desc, round(sum(bytes)/1048576) desc;

BACKUP_FILE.xlsx (10.14 KB)Hi tsangsir,
Please kindly find the attached file on 29-Oct-2021, data should be less than 3GB because it is incremental accumulative backup. It is not backup sense . Full backup is only every Monday.
Thank.

I can't see anything showing "every two days system is backup size same as full backup".
On 29/10, there were a FULL datafile backup (4134MB) and INCR1 datafile backup (190009). Its unreasonable that a INCRso much bigger than FULL.
Why's there a FULL backup on Fri??

1 - [Mitya], Yes i recognize like this. but the same script was applied with another database instance. It's working properly.
2- [Mitya], Yes it's not make sense that INCR size is more than Full bakcup.
3- [Mitya] , on Tuesday - Sunday, script was applied with Incremental accumulative backup only. but system is backup full on Friday( 29-Oct-2021) It is strange. Can you check on this issue?
Thank,
Mitya

Of course I can't check why you have a full backup on Fri, it's your system.
But the most likely reason is another backup job was configured by someone or at somewhere else.

Hi tsangsir,
Yes correct. on Friday system should backup Incremental but system execute script incremental accumulate already but it's records size full back.
and Script is executed by cronjob. no one configure another backup job.

Then no one configured, but a full backup was run.

Yes..Now i have monitored Tuesday, and Wendesday, Script was executed incremental Accumulate and size of backup is incremental. Let monitor tomorrow and see.