12C – Reduce Transportable Tablespace Downtime using Cross Platform Incremental Backup

Thanks to my Colleague Jaipal to introduce me to this Metalink Note: Doc ID 2005729.1

In a 12c and higher environment, to migrate data between systems that have different endian formats, with the least amount of application down time.

The first step is to copy a full back up from the source to the destination. Then, by using a series of incremental backups, each smaller than the last, the data at the destination system can be brought nearly current with the source system, before any downtime is required.

This procedure requires down time only during the final incremental backup and the meta-data export/import.

The high-level steps for Cross Platform Incremental Backup are:

1.  Initial setup
2.  Prepare phase(source data remains online)

1. 1. Backup (level=0) of tablespaces to be transported
   2. Transfer backup and other necessary setup files to destination system
   3. Restore datafiles on destination system endian format

3.  Roll Forward phase (source data remains online - Repeat this phase as many times as necessary to catch destination datafile copies up to source database)

1. 1. Create incremental backup on source system
   2. Transfer incremental backup and other necessary setup files to destination system
   3. Convert incremental backup to destination system endian format and apply the backup to the destination datafile copies
   4. Determine next_scn for next incremental backup
   5. Repeat steps until ready to transport the tablespace.

4.  Transport phase (source data is READ ONLY)

1. 1. Make tablespaces in source database READ ONLY
   2. Repeat the Roll Forward phase one final time
      • This step makes destination datafile copies consistent with source database and generates necessary export.
      • Time for this step is significantly shorter than traditional XTTS method when dealing with large data because the incremental backup size is smaller.
   3. Import metadata of objects in the tablespaces into destination database using Data Pump
   4. Make tablespaces in destination database READ WRITE

Thanks

Suresh