Upgrading from Z 1.8.9 -> 2.0.0-rc2 yields

ociexecute(): ORA-00942: table or view does not exist [include/db.inc.php:439]
SQL error [ORA-00942: table or view does not exist] in [SELECT hin.* FROM host_inventory hin WHERE (hin.hostid IN ('80324')) ]
ocifetchinto(): ORA-24374: define not done before fetch or execute and fetch [include/db.inc.php:570]

in any of the following menus,
Monitoring,
Dashboard | Overview | Web | Latest data | Triggers | Events

the culprit was the CREATE TABLE host_inventory failing due to

nvarchar2(2048) occurrences returning,

ORA-00910: specified length too long for its datatype

changing it to nvarchar2(1024) successfully created the table and cleared the errors.