Schema Compare can now use DBMS_REDEFINITION to add columns to the middle of the table rather than at the end. The “Sync column order with DBMS_REDEFINITION” feature has been renamed to “Add/Reorder columns with DBMS_REDEFINITION”.
Temporal Validity in Tables
The “Period For” clause in create/alter table scripts is now supported in script generation and in the create/alter table window in Toad. Oracle calls this feature “Temporal Validity” and it came out in version 126.96.36.199. Its purpose is to define valid time periods for rows in a table, and simplify the querying of rows that apply to specific periods. There’s a pretty good explanation and example of it here: https://oracle-base.com/articles/12c/temporal-validity-12cr1