xwiki with Oracle does not work with database username other than xwiki

I was not able to run XWiki against Oracle 10g using my default username, I've got error messages starting with following:

11:39:08,015 ERROR P1-19 http://localhost:38080/xwiki/bin/view/Main/ XWikiHibernateBaseStore:updateSchema:359 - Failed updating schema: ORA-01031: insufficient privileges

11:39:08,062 WARN P1-19 http://localhost:38080/xwiki/bin/view/Main/ JDBCExceptionReporter:logExceptions:71 - SQL Error: 942, SQLState: 42000
11:39:08,062 ERROR P1-19 http://localhost:38080/xwiki/bin/view/Main/ JDBCExceptionReporter:logExceptions:72 - ORA-00942: table or view does not exist

Note I am sure I had sufficient privileges for creating new tables.

Then I asked our DBA to create another account named "xwiki" and voila - everything worked correctly.