Is it possible to downgrade oracle 11.1.0.6.0 to 10.2.0.4.0?
The Compatible parameter need to be changed to "10.2.0"?
Today I have Compatible set to 10.2.0.4.0.
It's not clear on support.oracle if I need to change or not.
This document
http://www.oracle.com/technetwork/database/upgrade/upgrade11gr2-downgrade-methods-179029.pdf
state:
The major restriction on the downgrade script is that it cannot be run
if the COMPATIBLE parameter has been raised as part of, or after, the
upgrade. This is because raising the COMPATIBLE parameter will allow
on-disk changes that cannot be understood by the earlier version of
Oracle Database. For this reason, downgrades from Oracle Database 11g
Release 2 to Oracle Database 9i are not supported. Downgrades from
Oracle Database 11g Release 2 to the following versions are supported:
10.1.0.5 10.2.0.2, 10.2.0.3, 10.2.0.4, 10.2.0.5 11.1.0.6,
11.1.0.7
but this one
http://docs.oracle.com/cd/E11882_01/server.112/e17222/downgrade.htm#UPGRD12554
says:
If you are downgrading to Oracle Database 10g Release 2 (10.2), then
the COMPATIBLE initialization parameter must be set to 10.2.0 or
lower.
thx
Best Answer
Yes, it is possible, as stated in the 11.1 documentation:
Supported Releases for Downgrading
Oracle mentions 10.2.0, because ideally you need not to set anything more specific (more digits). This is explained in:
How To Change The COMPATIBLE Parameter And What Is The Significance? (Doc ID 733987.1)
If you set it to 10.2.0.4.0, the downgrade should be still successful to version 10.2.0.4, but not anything lower.