Re: COMPATIBILITY parameter

>Oops - forgot to mention that once you've set it you cannot change it to
>a lover value.
>The only (supported) vay is to do a full export, recreate the database,
>and then import.
>
>/Jesper

Hi, Jesper.
As far as I remember there is an option of ALTER DATABASE command:

ALTER DATABASE RESET COMPATIBILITY; from "Oracle7 Server SQL Reference" :

"... mark the database to be reset to an earlier version of Oracle7 when the database is next restarted.
Note: RESET COMPATIBILITY will not work unless you have successfully disabled Oracle7 features that affect backward compatibility. For more information on downgrading to an earlier version of Oracle7, see the _Upgrading and Downgrading_ chapter of Oracle7 Server Migration. "

from "Oracle7 Server Migration" :

"Downgrading to a Previous Release
After installing a new release, you can downgrade to a previous release by performing the following steps:

1. Execute the SHUTDOWN NORMAL command (for all instances, if running the Parallel Server).
2. Perform a full offline backup.
3. Execute the CONNECT INTERNAL command.
4. Execute the STARTUP RESTRICT command.
5. Disable certain features of the current release.
6. Run the appropriate scripts; To downgrade from the latest release to your previous release, start with the script for the latest release and run each incremental downgrade script until you reach your previous release. For example, to downgrade 7.1.3 to 7.0.13, you only run the following script: CAT7102D.SQL
7. Execute the ALTER DATABASE RESET COMPATIBILITY command.
8. Execute the ALTER DATABASE BACKUP CONTROLFILE TO TRACE command.
9. Execute the SHUTDOWN NORMAL command (for all instances, if running the parallel server).
10. Install the release to which you wish to downgrade.
11. Relink your applications using the libraries for the installed release.
12. Execute the CONNECT INTERNAL command.
13. Execute the STARTUP NOMOUNT RESTRICT command.
14. Execute the CREATE CONTROLFILE command to recreate the control file. For more information about the CREATE CONTROLFILE command, see Oracle7 Server SQL Reference.
15. Execute the ALTER DATABASE OPEN command.
16. Run the following scripts (at a session label of DBLOW for Trusted Oracle7): CATALOG.SQL CATPROC.SQL (run only if PL/SQL is installed) CATPARR.SQL (run only if the Parallel Server option is installed) CATREP.SQL (run only if the Replication option is installed) Warning: Remember to use the scripts that are supplied with the release to which you are downgrading.
17. Execute the ALTER SYSTEM DISABLE RESTRICTED SESSION command.
18. Execute the SHUTDOWN NORMAL command (for all instances, if running the Parallel Server).
19. Restart the database without enabling the new features (set the COMPATIBLE initialization parameter to the release value to which you have downgraded).
20. Perform a full offline backup.

Your database is now downgraded to your previous release."

Regards,
 Vasily.

--
                         Nemo solus sapit satis
         <<<<<<<<<<<<<<<<<<<<<<<<<< >>>>>>>>>>>>>>>>>>>>>>>>>>
Vasily Kraskovsky, Oracle DBA, Petersburg Express, St.Petersburg, Russia
                           vasily_at_kvr.spb.ru
                             kvr_at_pe.spb.ru