RMAN Backed up file recoginize

Sometimes we get backup and did not use TAG or format clause via RMAN.
However RMAN will give unique name for backup. After some period we need to clarify backup name,
which of them controlfile name, which of them backup datafile 1 etc.
For clarify Oracle RMAN backups, you need to use : list backup by file;

Let`s to look at example
take backup of current controlfile and spfile

RMAN> backup current controlfile spfile;


take backup of 1 data file of database, SYSTEM01.dbf

RMAN> backup datafile 1;


take backup of whole database and archivelog

RMAN> backup database plus archivelog;

[oracle@localhost 2010_08_12]$ ls -lh

total 1.3G

-rw-r----- 1 oracle oinstall 283M Aug 12 11:50 o1_mf_annnn_TAG20100812T115003_6676dx1p_.bkp

-rw-r----- 1 oracle oinstall 17K Aug 12 11:51 o1_mf_annnn_TAG20100812T115147_6676j4h5_.bkp

-rw-r----- 1 oracle oinstall 6.8M Aug 12 11:38 o1_mf_ncnnf_TAG20100812T113851_6675qw1y_.bkp

-rw-r----- 1 oracle oinstall 6.9M Aug 12 11:48 o1_mf_ncsnf_TAG20100812T114718_667694kt_.bkp

-rw-r----- 1 oracle oinstall 6.9M Aug 12 11:51 o1_mf_ncsnf_TAG20100812T115040_6676j23l_.bkp

-rw-r----- 1 oracle oinstall 349M Aug 12 11:47 o1_mf_nnndf_TAG20100812T114718_66767pnz_.bkp

-rw-r----- 1 oracle oinstall 585M Aug 12 11:51 o1_mf_nnndf_TAG20100812T115040_6676g0r9_.bkp

-rw-r----- 1 oracle oinstall 96K Aug 12 11:38 o1_mf_nnsnf_TAG20100812T113851_6675qxbt_.bkp

As you see, on OS level our backup up files name like o1_mf_****_TAG20100812T11****_667***_.bkp
And we can not recoginize names. Thereby we can use by list clause on list backup

RMAN> list backup by file;


List of Datafile Backups========================

File Key     TY LV S Ckp SCN    Ckp Time  #Pieces #Copies Compressed Tag
---- ------- -  -- - ---------- --------- ------- ------- ---------- ---
1    6       B  F  A 531440     12-AUG-10 1       1       NO         TAG20100812T115040
     3       B  F  A 531208     12-AUG-10 1       1       NO         TAG20100812T114718
2    6       B  F  A 531440     12-AUG-10 1       1       NO         TAG20100812T115040
3    6       B  F  A 531440     12-AUG-10 1       1       NO         TAG20100812T115040
4    6       B  F  A 531440     12-AUG-10 1       1       NO         TAG20100812T115040

List of Archived Log Backups
============================

Thrd Seq     Low SCN    Low Time  BS Key  S #Pieces #Copies Compressed Tag
---- ------- ---------- --------- ------- - ------- ------- ---------- ---
1    2       473040     10-AUG-10 5       A 1       1       NO         TAG20100812T115003
1    3       474104     10-AUG-10 5       A 1       1       NO         TAG20100812T115003
1    4       474117     10-AUG-10 5       A 1       1       NO         TAG20100812T115003
1    5       497563     10-AUG-10 5       A 1       1       NO         TAG20100812T115003
1    6       503686     10-AUG-10 5       A 1       1       NO         TAG20100812T115003
1    7       504368     10-AUG-10 5       A 1       1       NO         TAG20100812T115003
1    8       505036     10-AUG-10 5       A 1       1       NO         TAG20100812T115003
1    9       505706     10-AUG-10 5       A 1       1       NO         TAG20100812T115003
1    10      506370     10-AUG-10 5       A 1       1       NO         TAG20100812T115003
1    11      509812     10-AUG-10 5       A 1       1       NO         TAG20100812T115003
1    12      530702     12-AUG-10 5       A 1       1       NO         TAG20100812T115003
1    13      531425     12-AUG-10 8       A 1       1       NO         TAG20100812T115147

List of Control File Backups
============================

CF Ckp SCN Ckp Time  BS Key  S #Pieces #Copies Compressed Tag
---------- --------- ------- - ------- ------- ---------- ---
531470     12-AUG-10 7       A 1       1       NO         TAG20100812T115040
531228     12-AUG-10 4       A 1       1       NO         TAG20100812T114718
530896     12-AUG-10 1       A 1       1       NO         TAG20100812T113851

List of SPFILE Backups
======================

Modification Time BS Key  S #Pieces #Copies Compressed Tag
----------------- ------- - ------- ------- ---------- ---
12-AUG-10         7       A 1       1       NO         TAG20100812T115040
12-AUG-10         4       A 1       1       NO         TAG20100812T114718
12-AUG-10         2       A 1       1       NO         TAG20100812T113851

RMAN>

Please note that on "List of Datafile Backups" second row :

3       B  F  A 531208     12-AUG-10 1       1       NO         TAG20100812T114718

show that 1 datafile (system01.dbf) also was backed up before.