ORA-12838: cannot read/modify an object after modifying it in parallel

SQL> ALTER SESSION FORCE PARALLEL DML PARALLEL 4;

Session altered.

SQL> DELETE sh.customers1 WHERE cust_id>10000;

32000 rows deleted.

SQL> select * from sh.customers1;

select * from sh.customers1

* ERROR at line 1:

ORA-12838: cannot read/modify an object after modifying it in parallel

If you modified has table in parallel, then s query the content of that table you get an ORA-12838 error message.

How to solve?

SQL> ALTER SESSION FORCE PARALLEL DML PARALLEL 4;

Session altered.

SQL> DELETE sh.customers1 WHERE cust_id>10000;

32000 rows deleted.

SQL> commit or rollback

then

SQL> select * from sh.customers1;