Is Oracle 12.2 backward compatible with Oracle 12.1 Current Oracle DB I am using is 'Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit' and we have a use case for using 'Oracle 12.2.X.X.0'. We want to use the elongated object name lengths of 128 which come with Oracle 12.2

Is Oracle 12.2 backward compatible and supports everything on Oracle 12.1? Like Stored Procs, JBDC connections etc.

If new tables &amp; columns with long names on 12.2 start coming in, Can those tables be used in conjunction with tables created on 12.1 for joins etc., and can they start residing in the same schemas?
Here is the list of changes:

Behavior Changes, Deprecated and Desupported Features for Oracle Database 12c Release 2 (12.2)

Such basic functionality that you mentioned (table joins, stored procedures, JDBC connections) should of course work.

Sure, there are new features, and some changes, but I can not recall anything significant related to those areas that worked in 12.1 but did not in 12.2.