I am trying to disable the primary key constraint of DEPT table. That didn't work out. So I thought may be I could disable the foreign key of the referenced table (EMP)... .

However, it turned out that when I am working on the parent table, the child table is locked. Now, can anyone tell me how I can unlock from either EMP or DEPT table? Thanks!

The following errors demonstrate how the EMP table is locked.

1* ALTER TABLE scott.dept DISABLE CONSTRAINT DEPT_PRIMARY_KEY
2 /
ALTER TABLE scott.dept DISABLE CONSTRAINT DEPT_PRIMARY_KEY
*
ERROR at line 1:
ORA-02297: cannot disable constraint (SCOTT.DEPT_PRIMARY_KEY) - dependencies exist

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SQL>* ALTER TABLE scott.emp DISABLE CONSTRAINT EMP_FOREIGN_KEY
SQL> /
ALTER TABLE scott.emp DISABLE CONSTRAINT EMP_FOREIGN_KEY
*
ERROR at line 1:
ORA-00069: cannot acquire lock -- table locks disabled for EMP