I am using custom object types with Oracle PL/SQL, including several object types that inherit from a parent object. I have a TP_DOCUMENTS parent object, and child document types, such as TP_PUBLICATION, TP_CONTRACT, etc. We successfully created a table of TP_DOCUMENT and have added records of TP_PUBLICATION, TP_CONTRACT, and other child document records. However, I needed to create an additional type of document. Once I did this, it broke the DOCUMENTS table. How can I create additional child types, without breaking the table of the parent object (making me lose all the data previously contained in the parent object table!!)?

Here is some of my code:

create or replace TYPE           "TP_DOCUMENT" AS OBJECT 
( 
...fields go here
) NOT FINAL

create or replace TYPE           "TP_PUB_INSTRUCTION" UNDER TP_DOCUMENT()

CREATE TABLE DOCUMENTS OF TP_DOCUMENT

After creating these types (and others with additional fields), I created the table DOCUMENTs as shown above. I tried to create another sub-type, and the DOCUMENTS table broke.

MORE INFORMATION:

The error code message is as follows:

ORA-04063: table/view has errors

Cause:  Attempt to execute a stored procedure or use a view that has errors.  For stored procedures, the problem could be syntax errors or references to other, non-existent procedures.    For views,  the problem could be a reference in the view's defining query to a non-existent table.  Can also be a table which has references to non-existent or inaccessible types.   

Action: Fix the errors and/or create referenced objects as necessary. 

Thank you!

UPDATE WITH ANSWER FROM COMMENTER BELOW:

I had unfortunately dropped a Sub-Type using the Force option. That likely was the cause for why my Documents table was corrupted. In the future, I will use the Validate command (see answer below).