Thierry Beb, July 25, 2016 - 8:05 am UTC
OK.
So we don't need any of the archivelogs that were produced just before the start of the backup process. Just those produced during the process. And nothing after the last logswitch you made during this process.
A side question : does the DBW continue to write while the backup is running ?
Thanks again, your answer solve a recurring problem I had in my mind:)
July 25, 2016 - 8:57 am UTC
And nothing after the last logswitch you made during this process.
Well, if you want point-in-time recovery to some point after the backup finished, then yes, you do need them! Say the backup finished at 1am and you want to recover to 10am that day. You need the archivelogs from 1 -> 10am.
does the DBW continue to write while the backup is running ?
Assuming you're doing a hot backup with RMAN, yes.
Archived log necessary
Thierry Beb, July 29, 2016 - 7:10 am UTC
Hi,
First of all : many thanks for your answer and this site very very useful.
But when I make a full backup and then a "restore database preview",I see that the restore needs an archived log that was made before the backup started. If a checkpoint is made before the backup starts and because every undo information is written, why do we need this 'old' archived log.
Here below is the result of the command (with some .... to reduce the length)
RMAN> restore database preview
Starting restore at 29-07-16,08:55:41
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=347 device type=DISK
List of Backup Sets
===================
BS Key Type LV Size Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -----------------
5173 Full 3.47G DISK 00:01:09 28-07-16,23:01:22
List of Datafiles in backup set 5173
File LV Type Ckp SCN Ckp Time Name
---- -- ---- ---------- ----------------- ----
1 Full 9475559245562 28-07-16,23:00:14 E............DATAFILE\O1_MF_SYSTEM_8GZP56NR_.DBF
2 Full 9475559245562 28-07-16,23:00:14 .........ILE\O1_MF_SYSAUX_8GZP56P6_.DBF
......
10 Full 9475559245562 28-07-16,23:00:14 ........0PP\DATAFILE\BIDON-TBS
Backup Set Copy #1 of backup set 5173
Device Type Elapsed Time Completion Time Compressed Tag
----------- ------------ ----------------- ---------- ---
DISK 00:01:09 28-07-16,23:01:22 NO BACKUP_DB10PP_0000_072816110001
List of Backup Pieces for backup set 5173 Copy #1
BP Key Pc# Status Piece Name
------- --- ----------- ----------
9073 1 AVAILABLE .....B10PP\BACKUPSET\2016_07_28\O1_MF_NNNDF_BACKUP_DB10PP_0000_0_CSNWLYTK_.BKP
..........
9077 5 AVAILABLE ......B10PP\BACKUPSET\2016_07_28\O1_MF_NNNDF_BACKUP_DB10PP_0000_0_CSNWNTYD_.BKP
using channel ORA_DISK_1
List of Archived Log Copies for database with db_unique_name DB10PP
=====================================================================
Key Thrd Seq S Low Time
------- ---- ------- - -----------------
<u><b>16399 1 82 A 28-07-16,22:00:58
Name: E:\APP\DB\FAST_RECOVERY_AREA\DB10PP\ARCHIVELOG\2016_07_28\O1_MF_1_82_CSNWOD3O_.ARC</b></u>
16401 1 83 A 28-07-16,23:01:31
Name: E:\APP\DB\FAST_RECOVERY_AREA\DB10PP\ARCHIVELOG\2016_07_29\O1_MF_1_83_CSO7S9T2_.ARC
16403 1 84 A 29-07-16,02:11:21
Name: E:\APP\DB\FAST_RECOVERY_AREA\DB10PP\ARCHIVELOG\2016_07_29\O1_MF_1_84_CSO7SCTG_.ARC
Media recovery start SCN is 9475559245562
Recovery must be done beyond SCN 9475559245724 to clear datafile fuzziness
Finished restore at 29-07-16,08:55:43
RMAN>
August 08, 2016 - 7:07 am UTC
From what I can see there, that first archive spans 22:00:58 to 23:01:31.
Your backup completed at 23:01:22, so that archive might be relevant.
OK and thanks
A reader, August 11, 2016 - 9:39 am UTC
Ok so simple. I should have read the name of the column (low_time) ! Thanks.
I have a general remark concerning the Oracle documentation. Sketches, graphs of Oracle workflows and Oracle processes are really too rare. Often a good schema is better than thousands words.
Thanks again for your help