Hello.
This features i didn't see in previous versions of PL/SQL Developer.

1. If we have a table with DDL like
... partition by range (DATE_COLUMN) interval (numtodsinterval (1, 'DAY')) ...
then with function dbms_metadata.get_ddl or by open context menu on table and clicking "DBMS_Metadata -> DDL" we can get full DDL for a table with this code part.

But if we open context menu on a table, select "View" command and in the window that appears clicking on "View SQL", then there is no word like "interval", just "partition by range (DATE_COLUMN)" and full partition list.

Also it will be usefull show "interval (numtodsinterval (1, 'DAY'))" on the tab "Partitions", on the right of 'Type' and 'Columns' properties at top part of window "View table".

2. It will be usefull to show the number of rows for every partitions and subpartitoin, like Toad for Oracle do. It gets the same *_tab_partitions & *_tab_subpartitions views and just showing values from "NUM_ROWS" and "LAST_ANALYZED" columns.

3. Also, like in Toad, there maybe will be better show subpartitions in single tab with partitions, where subpartitions placed above their partition in 2-level tree with '-' and '+' signs for collaps and expand: