RMAN Sparse Backup Is Full Size (not Sparse Data) (Doc ID 2437886.1)

Last updated on APRIL 17, 2023

Applies to:

Symptoms

Running rman backup of a CDB with 2 Test Primaries in DATA1 disk group and 5 new Sparse Clones with files in Sparse1 disk group.

SQL> select substr(name,1,8) FN, round(sum(bytes)/1024/1024/1024) size_GB from v$datafile
        group by substr(name,1,8);

FN SIZE_GB
-------------------------------- ----------
+DATA1/L 236
+SPARSE1 637

RMAN backup job should only backup data1 files and delta blocks in sparse (all thin clones are new so delta blocks should be small)

run {
backup AS SPARSE BACKUPSET
incremental level 0
filesperset=1
section size 64G
format '/nas/<path>/df.d%d.t%t.s%s.p%p'
(database);
}

Size of backupset files are much larger than they should be for a sparse database backup.  This started after applying the 12.2.0.1.180116 DBJAN2018RU patchset to to the database.

$ du -sh ./6496690*
727G ./6496690

Cause

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