while upgrade from 11.1.0.7 to 11.2.0.2
there was slowness in dbua taking more than 15 hours. After truncating SYS.AUD$
and noarchivelog mode , dbua completed in less than a hour.

Some possible reasons which will fix the issue:
- Truncate large SYS.AUD$ or SYS.FGA_LOG$ table
- database in archivelog mode(Upgrade in noarchivelog mode)
- flashback database logging on
- database triggers (i.e. if you do ddl auditing)
- maybe also disable change block tracking