Confluence incompatible with DB2 HADR (High Availability Disaster Recovery)

Confluence overrides the Hibernate definition of CLOB and BLOB columns in the
DB2Dialect class and turns off HADR logging using the "NOT LOGGED" option.

This is not obvious to installation and support personnel as this is done behind the scenes.
During a HADR switchover, any CLOB and BLOB field type is not transmitted to the standby
DB2 database server, resulting in the Disaster Recovery site becoming in-consistent.

Atlassian should provide a checkbox at installation time to optionally disable logging
and leave logging on as the default condition (as does Hibernate).

Failing that possibility, this behaviour should be documented in the installation guide
under the DB2 section to warn installers that manual intervention is involved by a
database administrator "after the fact" to re-enable logging for CLOB and BLOB fields
once the Confluence database is created.

Issue previously created under CSP-62596 and CSP-62913, moved here at Atlassian Support's request.