The Library is currently in the process of being upgraded from Oracle Database Version to 126.96.36.199
and version 18.0 is going to be available soon.
Demos are being upgraded to reflect the new Container paradigm as well as EBR (Edition Based Redefinition) and may contain references to CDBs, PDBs,
and other objects you may not be familiar with such as CDB_OBJECTS_AE:
Welcome to 12c and beyond.
Have you viewed the Library's main Table of Contents? If not ... [Click Here]
... scroll down the page and you will find links to the largest collection of Oracle Database demos on the net.