Nested tables and referential constraints question

Hi!

Is it at all possible to define referential constraints inside nested tables?

I tried this program:

CREATE TYPE X AS OBJECT (
  X_A NUMBER PRIMARY KEY,
  X_B NUMBER
);
/

CREATE TABLE XS OF X;
CREATE TYPE Y AS OBJECT (
  Y_X_REF REF X, -- refers to a X object );
/

CREATE TYPE NESTED_Y AS TABLE OF Y;
/

CREATE TABLE MY_TAB (
  MY_TAB_KEY NUMBER PRIMARY KEY,
  YS NESTED_Y
)
NESTED TABLE YS STORE AS Y_TAB; ALTER TABLE Y_TAB ADD (
  CONSTRAINT FK FOREIGN KEY( Y_X_REF ) REFERENCES XS );

The alter table command fails with ORA-30730:

The online documentation says about this error:

ORA-30730 referential constraint not allowed on nested table column

Cause: An attempt was made to define a referential

       constraint on a nested table column.

Action: Do not specify referential constraints on nested table

        columns.

This is not very informative... why is it not allowed? This seems an arbitrary restriction to me and it makes nested tables a lot less attractive.
Since we thought nested tables were the solution to all (well...) our problems with our current project, we would really like to know:

• Have I got it all wrong? Is it indeed possible?
• Does anyone know of a workaround?
• Will this restriction be lifted in the near future? (We are currently using Oracle 8.1.5)

Any help on this would be greatly appreciated.

  /Stefan Received on Mon Jul 05 1999 - 11:31:08 CDT