ORA-30556错误

SQL> CREATE TABLE TEST2 (A NUMBER(9,0), B VARCHAR2(20) not null);

Table created.

SQL> CREATE INDEX test2index1 ON test2(UPPER(B));

Index created.

SQL> alter table TEST2 modify B VARCHAR2(24);
alter table TEST2 modify B VARCHAR2(24)
                         *
ERROR at line 1:
ORA-30556: functional index is defined on the column to be modified


SQL> select * from user_ind_columns where table_name='TEST2';

INDEX_NAME                     TABLE_NAME                     COLUMN_NAME
------------------------------ ------------------------------ ------------------
TEST2INDEX1                    TEST2                          SYS_NC00003$

SQL> drop index test2index1;

Index dropped.

SQL> alter table TEST2 modify B VARCHAR2(24);

Table altered.

SQL> CREATE INDEX test2index1 ON test2(UPPER(B));

Index created.