Jan 12 2010
Edition-Based Redefinition
Upgrading critical applications can be very difficult. One of the main problems is that for reasons of availability, long downtimes cannot be periodically scheduled. Therefore, for such applications, it is desirable to implement online upgrades. This requires that the application in question, as well as any software used by the application (e.g. the database engine) all support online upgrades. Oracle has recognized this problem for years. Unfortunately, up to and including Database 11g Release 1, only a limited number of features have been implemented for that purpose. As of Oracle Database 11g Release 2, this situation has changed greatly. With edition-based redefinition, Oracle Database offers real support for implementing online upgrades. The aim of the paper Edition-Based Redefinition, that I just put online here, is to provide an overview of this new feature.
February 2nd, 2010 at 8:04 pm
[...] edition based redefinition detailed analysis Christian Antognini-Edition Based Redefinition Leave a [...]
February 3rd, 2010 at 10:38 pm
How to change Session Edition without downtime (without reconnect to database) ? E.g. a JDBC connection.
I couldn’t find it after a quick scan of Oracle Documentation.
February 4th, 2010 at 9:27 am
Hi Charlie
AFAIK there is no specific API for this. So, you have to execute a regular ALTER SESSION statement. E.g.:
statement = connection.createStatement(); statement.execute("ALTER SESSION SET edition = " + edition);HTH
Chris
February 4th, 2010 at 7:55 pm
Please correct me if I’m wrong. So that means we cannot change other session’s Edition online.
We either use application to send the “ALTER SESSION SET edition = ” command to every connected session, or use database logon trigger to set Edition and reconnect (restart the application).
“AFAIK”, learned a new abbr. today. ^_^
February 4th, 2010 at 11:58 pm
Hi Charlie
The only way to change the session edition is to execute an ALTER SESSION statement or through the SET_EDITION_DEFERRED procedure in the DBMS_SESSION package.
However, to change the default edition at the database level, it is possible to change the DEFAULT_EDITION database property. It goes without saying that such a change do not impact connected sessions.
HTH
Chris
February 5th, 2010 at 12:47 am
OK Chris,
Our deployment procedure will be:
1) roll in new version PL/SQL package and other database object changes.
2) change the DEFAULT_EDITION database property.
3) Application reconnect to database, (restart the connection pool).
Thanks,
Charlie