Issue

• Oracle added support for the IDENTITY type in Oracle 12c (See the New Features Guide 2.1.6.3 IDENTITY Columns
• The new Oracle type is meant to behave similarly to IDENTITY types in other databases (e.g. Microsoft SQL Server) which are already supported by Hibernate when appropriately configured

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private Long id;

• The following exception is raised if entities with IDENTITY type mappings (as above) are defined when attempting to create an entity factory using the Oracle dialect(s):

org.hibernate.MappingException: org.hibernate.dialect.Oracle10gDialect does not support identity key generation
    at org.hibernate.dialect.Dialect.getIdentityColumnString(Dialect.java:772)
    at org.hibernate.dialect.Dialect.getIdentityColumnString(Dialect.java:762)
    at org.hibernate.mapping.Table.sqlCreateString(Table.java:505)
    at org.hibernate.cfg.Configuration.generateSchemaCreationScript(Configuration.java:1038)
    at org.hibernate.tool.hbm2ddl.SchemaExport.<init>(SchemaExport.java:125)
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:501)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1794)
    at org.hibernate.ejb.EntityManagerFactoryImpl.<init>(EntityManagerFactoryImpl.java:96)
    at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:914)
    ...