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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.
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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
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<Insert Picture Here> 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
High Availability Make planned changes to software Change application’s database objects Change objects’ meaning:patching and upgrading Online Application Upgrade– the final piece of the High Availability jigsaw puzzle Survivehardware failure Change infrastructure:Operating systemOracle 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 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 thepre-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
<Insert Picture Here> Case study
Case study • The HR sample schema, as shipped by Oracle Corp, still thinks that the USA is the only countryin the world • Diana Lorentz 590.423.5567 • John Russell 011.44.1344.429268
<Insert Picture Here> Case study –The edition-based redefinition exercise proper
Employees Show_ Employees Ph. ID … Employees_ Starting point.Pre-upgrade app in normal use. Pre_Upgrade
Show_ Employees Employees Employees Show_ Employees Ph. ID … Employees_ Start the edition-based redefinition exercise.Create the new edition as the child of the existing one. Post_Upgrade Pre_Upgrade
Show_ Employees Employees Employees Show_ Employees Ph. ID … Cntry # Employees_ Create the replacement columns in the underlying table.The editioning view shieldsthe pre-upgrade app from this change. Post_Upgrade Pre_Upgrade
Employees Employees Show_ Employees Show_ Employees Ph. ID … Cntry # Employees_ Change Employees to selectthe new columns.Change Show_Employeess to implement the new behavior. Post_Upgrade Pre_Upgrade
Employees Employees Fwd Xed Show_ Employees Show_ Employees Ph. ID … Cntry # Employees_ Create the forward crossedition trigger. Post_Upgrade Pre_Upgrade
Employees Employees Fwd Xed Rvrs Xed Show_ Employees Show_ Employees Ph. ID … Cntry # Employees_ Create the reverse crossedition trigger. Post_Upgrade Pre_Upgrade
Fwd Xed Employees Employees Rvrs Xed Show_ Employees Show_ Employees Apply the transform to the data for the new app to use Post_Upgrade Pre_Upgrade Ph. ID … Cntry # Employees_
Employees Employees Fwd Xed Rvrs Xed Show_ Employees Show_ Employees Ph. ID … Cntry # Employees_ Hot rollover period. Post_Upgrade Pre_Upgrade
Employees Show_ Employees The Pre_Upgrade editionis retired.The edition-based redefinition exercise is complete. Post_Upgrade Pre_Upgrade Show_Employees Employees Ph. ID … 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
Q A & <Insert Picture Here>