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					Online Application Upgrade Using Edition-Based Redefinition
Alan Choi
PL/SQL, Database Sever Technology
http://www.oracle.com/technology/products/database/index.html
The following is intended to outline our general
product direction. It is intended for information
purposes only, and may not be incorporated into any
contract. It is not a commitment to deliver any
material, code, or functionality, and should not be
relied upon in making purchasing decisions.
The development, release, and timing of any
features or functionality described for Oracle’s
products remain at the sole discretion of Oracle.
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                                        Tudor Dumitras

                          “…for the past 30 years, online
                        upgrades have been a solution in
                                  search of a problem...”
Industrial Demand for Online Application Upgrade


•   Electricity Utility Management System
•   Support System for Global Company
•   Manufacturing Industry – assembly line
•   Online Business
•   Banking System
  Online Application Upgrade
   – the final piece of the High Availability jigsaw puzzle


                            High Availability

   Make planned                                             Survive
changes to software                                     hardware failure



Change application’s                Change infrastructure:
 database objects                     Operating system
                                      Oracle Database



    Change objects’
                                                Change objects’
       meaning:
                                             physical characteristics
patching and upgrading
 Online Application Upgrade

• Oracle Database 11g Release 2 introduces
  revolutionary new capabilities that allow online
  application upgrade with uninterrupted availability of
  the application

• The pre-upgrade application and the post-upgrade
  application can be used at the same time

• End-user sessions therefore enjoy hot rollover
 The Challenge

• Essence of data must be consistent between pre-
  upgrade and post-upgrade applications
  – Existing data must be visible to both applications

  – Transactions done by the users of the pre-upgrade
    application must by reflected in the post-upgrade application

  – For hot rollover, transactions done by the users of the post-
    upgrade application must by reflected in the pre-upgrade
    application

• The installation of the upgrade into the production
  database must not perturb live users of the
  pre-upgrade application
  – Many objects must be changed in concert. The changes must
    be made in privacy
 The solution: edition-based redefinition

• 11.2 brings these revolutionary new features: the
  edition, the editioning view, and the crossedition
  trigger

  – Changes in stored procedures and views are installed in the
    privacy of a new edition

  – Data changes are made safely by writing only to new columns
    or new tables not seen by the old edition
     • An editioning view exposes a different projection of a table
       into each edition to allow each to see just its own columns
     • A crossedition trigger propagates data changes made by
       the old edition into the new edition’s columns, or (in hot-
       rollover) vice-versa
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Case study
 Case study


• The HR sample schema, as shipped by Oracle Corp,
  still thinks that the USA is the only country
  in the world
  – Diana Lorentz   590.423.5567
  – John Russell    011.44.1344.429268
Case study
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Case study –
The edition-based redefinition
exercise proper
Starting point.
Pre-upgrade app in normal use.




                                             Pre_Upgrade

                                 Employees         Show_ Employees


 ID   Ph.   …




 Employees_
Start the edition-based                     Post_Upgrade
redefinition exercise.
                                Employees          Show_ Employees
Create the new edition as the
child of the existing one.




                                            Pre_Upgrade

                                Employees          Show_ Employees


 ID   Ph.   …




 Employees_
Create the replacement                      Post_Upgrade
columns in the underlying
table.                          Employees          Show_ Employees

The editioning view shields
the pre-upgrade app from this
change.




                                            Pre_Upgrade

                                Employees          Show_ Employees


 ID   Ph.   …   Cntry   #




 Employees_
Change Employees to select                Post_Upgrade
the new columns.
                              Employees          Show_ Employees


Change Show_Employeess to
implement the new behavior.




                                          Pre_Upgrade

                              Employees          Show_ Employees


 ID   Ph.   …   Cntry   #




 Employees_
Create the forward crossedition               Post_Upgrade
trigger.
                                  Employees          Show_ Employees



                                  Fwd Xed




                                              Pre_Upgrade

                                  Employees          Show_ Employees


 ID   Ph.   …   Cntry   #




 Employees_
Create the reverse crossedition               Post_Upgrade
trigger.
                                  Employees          Show_ Employees



                                  Fwd Xed
                                               Rvrs Xed




                                              Pre_Upgrade

                                  Employees          Show_ Employees


 ID   Ph.   …   Cntry   #




 Employees_
Apply the transform to the data               Post_Upgrade
for the new app to use
                                  Employees          Show_ Employees



                                  Fwd Xed
                                               Rvrs Xed




                                              Pre_Upgrade

                                  Employees          Show_ Employees


 ID   Ph.   …   Cntry   #




 Employees_
Hot rollover period.                     Post_Upgrade

                             Employees          Show_ Employees



                             Fwd Xed
                                          Rvrs Xed




                                         Pre_Upgrade

                             Employees          Show_ Employees


 ID   Ph.   …    Cntry   #




 Employees_
The Pre_Upgrade edition                      Post_Upgrade
is retired.
                                 Employees          Show_ Employees


The edition-based redefinition
exercise is complete.




                                             Pre_Upgrade

                                 Employees          Show_Employees


 ID   Ph.   …    Cntry    #




 Employees_
Conclusion


• Large, mission critical applications can now be continuously
  available while a patch or an upgrade is installed

   – The pre-upgrade application and the post-upgrade application can
     be used at the same time

• Beta customers tested it, declare it fit for their purpose, and hope
  to enable online application upgrade through EBR

• White paper available at
  http://www.oracle.com/technology/deploy/availability/pdf/edition_
  based_redefinition.pdf
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Q&A

				
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posted:9/3/2012
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