Transcript Online Application Upgrade Using Edition

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
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material, code, or functionality, and should not be
relied upon in making purchasing decisions.
The development, release, and timing of any
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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
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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
changes to software
Change application’s
database objects
Change objects’
meaning:
patching and upgrading
Survive
hardware failure
Change infrastructure:
Operating system
Oracle Database
Change objects’
physical characteristics
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 preupgrade 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 postupgrade 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 hotrollover) 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
– John Russell
590.423.5567
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
ID
Ph.
…
Employees_
Show_ Employees
Start the edition-based
redefinition exercise.
Create the new edition as the
child of the existing one.
Post_Upgrade
Employees
Show_ Employees
Pre_Upgrade
Employees
ID
Ph.
…
Employees_
Show_ Employees
Create the replacement
columns in the underlying
table.
Post_Upgrade
Employees
Show_ Employees
The editioning view shields
the pre-upgrade app from this
change.
Pre_Upgrade
Employees
ID
Ph.
…
Employees_
Cntry
#
Show_ Employees
Change Employees to select
the new columns.
Post_Upgrade
Employees
Show_ Employees
Change Show_Employeess to
implement the new behavior.
Pre_Upgrade
Employees
ID
Ph.
…
Employees_
Cntry
#
Show_ Employees
Create the forward crossedition
trigger.
Post_Upgrade
Employees
Show_ Employees
Fwd Xed
Pre_Upgrade
Employees
ID
Ph.
…
Employees_
Cntry
#
Show_ Employees
Create the reverse crossedition
trigger.
Post_Upgrade
Employees
Show_ Employees
Fwd Xed
Rvrs Xed
Pre_Upgrade
Employees
ID
Ph.
…
Employees_
Cntry
#
Show_ Employees
Apply the transform to the data
for the new app to use
Post_Upgrade
Employees
Show_ Employees
Fwd Xed
Rvrs Xed
Pre_Upgrade
Employees
ID
Ph.
…
Employees_
Cntry
#
Show_ Employees
Hot rollover period.
Post_Upgrade
Employees
Show_ Employees
Fwd Xed
Rvrs Xed
Pre_Upgrade
Employees
ID
Ph.
…
Employees_
Cntry
#
Show_ Employees
The Pre_Upgrade edition
is retired.
Post_Upgrade
Employees
Show_ Employees
The edition-based redefinition
exercise is complete.
Pre_Upgrade
Employees
ID
Ph.
…
Employees_
Cntry
#
Show_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