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12C - Reduce Transportable Tablespace Downtime using Cross Platform Incremental Backup (Doc ID 2005729.1)

Last updated on SEPTEMBER 21, 2021

Applies to:

Oracle Database Cloud Exadata Service - Version N/A and later
Oracle Database Backup Service - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Oracle Database Cloud Service - Version N/A and later
Gen 1 Exadata Cloud at Customer (Oracle Exadata Database Cloud Machine) - Version N/A and later
Linux x86-64
Updated 05-Jun-2017 -- Version 3



Purpose

Consider using the new release of this procedure, version 4. This version has drastically simplified the steps and procedure. Before proceeding, review:
V4 Reduce Transportable Tablespace Downtime using Cross Platform Incremental Backup <Note 2471245.1>

No bug fixs or diagnostics will be conducted on this older version of XTTs.   Unless absolutely necessary, only V4 of XTTs should be used.

 

This article covers the steps needed to use Cross Platform Transportable Tablespaces (XTTS) with RMAN incremental backups, 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 backup 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.

This document describes the 12c procedures for Cross Platform Incremental Backup. For the 11g procedures, see <Note:1389592.1>.

The Cross Platform Incremental Backup feature does not affect the amount of time it takes to perform other actions for XTTS, such as metadata export and import.  Hence, databases that have very large amounts of metadata (DDL), such as Oracle E-Business Suite and other packaged applications, will see limited benefit from Cross Platform Incremental Backup because migration in these environments is typically dominated by metadata operations, not datafile transfer and conversion.

 

Only those database objects that are physically located in the tablespaces that are being transported will be copied to the destination system. If you need for other objects to be transported, that are located in different tablespaces (such as, for example, pl/sql objects, sequences, etc., that are located in the SYSTEM tablespace), you can use data pump to copy those objects to the destination system.

 

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

1.  Initial setup

2.  Prepare phase (source data remains online)

    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. 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.  
NOTE:  In Version 3, if a datafile is added to the tablespace OR a new tablespace name is added to the xtt.properties file, a warning and additional instructions will be required.  

 4.  Transport phase (source data is READ ONLY)

    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

 

Scope

Consider using the new release of this procedure, version 4. This version has drastically simplified the steps and procedure. Before proceeding, review:
V4 Reduce Transportable Tablespace Downtime using Cross Platform Incremental Backup <Note 2471245.1>

The source system may be any platform provided the prerequisites referenced and listed below for both platform and database are met. 

If you are migrating from a little endian platform to Oracle Linux, then the migration method that should receive first consideration is Data Guard.  See <Note 413484.1> for details about heterogeneous platform support for Data Guard between your current little endian platform and Oracle Linux.

Details

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In this Document
Purpose
Scope
Details
 Overview
 Cross Platform Incremental Backup Supporting Scripts
 Prerequisites
 Troubleshooting
 Known Issues
 Transport Tablespaces with Reduced Downtime using Cross Platform Incremental Backup
 Conventions Used in This Document
 Phase 1 - Initial Setup
 Step 1.1 - Install the destination database software and create the destination database
 Step 1.2 - Identify tablespaces to be transported
 Step 1.3 - Install xttconvert scripts on the source system
 Step 1.4 - Create necessary directories
 Step 1.5 - Configure xtt.properties on the source system
 Step 1.6 - Copy xttconvert scripts and xtt.properties to the destination system<
 Step 1.7 - Set TMPDIR environment variable
 Phase 2 - Prepare Phase
 Step 2.1 - Run the backup on the source system
 Step 2.2 - Transfer the following files to the destination system:
 Step 2.3 - Restore the datafiles on the destination system
 Phase 3 - Roll Forward Phase
 Step 3.1 - Create an incremental backup of the tablespaces being transported on the source system
 Step 3.2 - Transfer incremental backup to the destination system
 Step 3.3 - Apply the incremental backup to the datafile copies on the destination system
 Step 3.4 - Determine the FROM_SCN for the next incremental backup
 Step 3.5 - Repeat the roll forward phase 3 (3.1 - 3.4) or proceed to phase 4, final incremental backup
 Phase 4 - Final Incremental Backup
 Step 4.1 - Alter source tablespace(s) READ ONLY in the source database
 Step 4.2 - Create the final incremental backup and  export file for transfer to the destination
 Step 4.3 - Apply last incremental backup to destination datafiles
 Phase 5 - Transport Phase:  Import Object Metadata into Destination Database
 Step 5A - Import existing dump file.
 Step 5A.1 - Create datapump directory and grant privilege:
 Step 5A.2 Modify and execute impdp command:
 Step 5B - Import using network link.
 Step 5B.1 - Generate new xttplugin.txt for network import
 Step 5B.2 - Create a database link on destination database:
 Step 5B.3 - Modify and execute Impdp command:
 Phase 6 - Validate the Transported Data
 Step 6.1 Check tablespaces for corruption
 Step 6.2 - Alter the tablespace(s) READ WRITE in the destination database
 Phase 7 - Cleanup
 Appendix
 Description of Perl Script xttdriver.pl Options
 Description of Parameters in Configuration File xtt.properties
 Change History
References

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