Confluence failing with SQL exception after upgrade

[Brainsquare Atlassian Expert]

I accidentally upgraded Confluence from 5.9.10 to 6.3.3 while the database was unavailable, and now the atlassian-confluence.log file shows SQL exceptions, like these ones:

ERROR: relation "auditrecord" does not exist
...
ERROR: column space1_.lowerspacekey does not exist

Is there a way to fix the database scheme?

[AnnWorley]

I understand you ran an upgrade while the database was unavailable and now you have a case where a 6.3.3 instance is trying to run connected to a 5.9.10 database. I am assuming the application did not start and there is no new data, as there are quite a few database changes between 5.9.10 and 6.3.3. 

 Unless I am mistaken about what the issue is, the best solution is to restore the database and home directory from backup and then run the upgrade again while the database is available.

Please see the Before you Begin section on Upgrading Confluence for a good checklist, as the upgrade past 6.x is a major one.