Every release has some Major changes , which we usually says New Features.Some of these features dominate the version, For example 11g R1 has SPA , DB Replay Active standby etc. Same this Oracle Release ( Oracle Database 11g Release 2 ) has some New features for which this release will be known in feature. These features are "Edition based redefination"
Most likely these features designed to give big support to APPS upgrade ( ie Oracle E-Business suite upgrade). When you upgrade APPS database , it need lots of down time , hope, using these new features APPS upgrade will take less time in future.
This feature will allow application upgrade( AS DBA , i would prefer to say Online Database object upgrade) with Minimum down time or may be zero down time. I consider this feature as one step toward ZERO DOWN time for application upgrade.
In 10g statistics collected on table published immediatly, That usually cause lots of performance issue. In oracle 11g r1 there is feature, for collecting stats on tables and publishing stats , as per need to avoid performance issue due to stats collection.
Taking similar feature to next step , 11g R2 has feature "REDEFINITION" , which upgrades objects , but not published immediately, also database can have multiple Editions of objects definition. Of-course there are, some limitation
Check Default Edition
Changing Edition at session or Database level
SQL> ALTER SESSION SET EDITION=ora$base;
Grant create or drop edition to user
SQL> GRANT CREATE ANY EDITION, DROP ANY EDITION to virag;
Enable Edition on schema / User
SQL> ALTER USER virag ENABLE EDITIONS force;
Of-course there are, some limitation......
Will add more ......soon , for How to...
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