A nice Oracle Database 12c New Feature enhances the multisection backup, introduced in 11g: You can use it now for image copies also!
RMAN> report schema; using target database control file instead of recovery catalog Report of database schema for database with db_unique_name PRIMA List of Permanent Datafiles =========================== File Size(MB) Tablespace RB segs Datafile Name ---- -------- -------------------- ------- ------------------------ 1 347 SYSTEM YES /u01/app/oracle/oradata/prima/system01.dbf 2 235 SYSAUX NO /u01/app/oracle/oradata/prima/sysaux01.dbf 3 241 UNDOTBS1 YES /u01/app/oracle/oradata/prima/undotbs01.dbf 4 602 USERS NO /u01/app/oracle/oradata/prima/users01.dbf List of Temporary Files ======================= File Size(MB) Tablespace Maxsize(MB) Tempfile Name ---- -------- -------------------- ----------- -------------------- 1 40 TEMP 32767 /u01/app/oracle/oradata/prima/temp01.dbt RMAN> configure device type disk parallelism 2; new RMAN configuration parameters: CONFIGURE DEVICE TYPE DISK PARALLELISM 2 BACKUP TYPE TO BACKUPSET; new RMAN configuration parameters are successfully stored RMAN> backup section size 301m as copy datafile 4; Starting backup at 29-JUN-15 using channel ORA_DISK_1 using channel ORA_DISK_2 channel ORA_DISK_1: starting datafile copy input datafile file number=00004 name=/u01/app/oracle/oradata/prima/users01.dbf backing up blocks 1 through 38528 channel ORA_DISK_2: starting datafile copy input datafile file number=00004 name=/u01/app/oracle/oradata/prima/users01.dbf backing up blocks 38529 through 77056 output file name=/u02/fra/PRIMA/datafile/o1_mf_users_bs2v934z_.dbf tag=TAG20150629T180658 channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:15 output file name=/u02/fra/PRIMA/datafile/o1_mf_users_bs2v934z_.dbf tag=TAG20150629T180658 channel ORA_DISK_2: datafile copy complete, elapsed time: 00:00:15 Finished backup at 29-JUN-15 RMAN> host 'ls -rtl /u02/fra/PRIMA/datafile/'; total 616468 -rw-r-----. 1 oracle oinstall 631250944 Jun 29 18:07 o1_mf_users_bs2v934z_.dbf host command complete
We use backupsets by default now especially also upon the DUPLICATE DATABASE command, which leads finally to image copies of course.
#1 von Mikhail Velikikh am Juni 30, 2015 - 09:38
@ You can use it now for image copies also!
May be it’s slightly offtopic, but I would like to ask you about usage of section size with cross-platform migration.
Do you have any information about the SECTION SIZE for XTTS migration?
I would like to describe the issue that I faced 3 years ago.
My company decided to migrate multi TB database from HP-UX IA64 to Linux x86-64.
We are used Oracle 184.108.40.206 version.
I utilized XTTS to accomplish this task.
At one of the steps I executed command CONVERT DATAFILE TO PLATFORM on the Linux host.
Most tablespaces was smallfile with datafile sizes below 32Gb, but one of them was bigfile tablespace with size 300Gb.
AFAIK CONVERT DATAFILE didn’t support SECTION SIZE parameter.
To perform migration within allotted downtime window, I had to migrate all data from the bigfile tablespace to the smallfile tablespace first.
After some time I discovered that Oracle had announced the Cross Platform Incremental backups.
It could extremely simplify the migration, but our migration was performed without this.
In the 220.127.116.11 Oracle made an enhancements to the Cross-platform backup and restore.
As I see in the documentation for BACKUP command:
When you use either the FOR TRANSPORT or TO PLATFORM clause, you cannot use the following clauses of the BACKUP command:
So I suppose that CONVERT DATAFILE command still cannot utilize SECTION SIZE.
It’s a serious restriction for customers that use a bigfile tablespaces.
#2 von Tim am Januar 8, 2016 - 21:31
I am wondering about your image. Shouldn’t there be an additional level? I would have thought the channels would have written backup pieces and the backup pieces would be part of one backup set.