truncate table时发生ORA-02266错误

10:07:26 SQL> conn utcore/oss
Connected.
10:07:44 SQL> truncate table mapevent;
truncate table mapevent
*
ERROR at line 1:
ORA-02266: unique/primary keys in table referenced by enabled foreign keys

10:09:53 SQL> !oerr ora 2266
02266, 00000, "unique/primary keys in table referenced by enabled foreign keys"
// *Cause: An attempt was made to truncate a table with unique or 
// primary keys referenced by foreign keys enabled in another table.
// Other operations not allowed are dropping/truncating a partition of a
// partitioned table or an ALTER TABLE EXCHANGE PARTITION.
// *Action: Before performing the above operations the table, disable the 
// foreign key constraints in other tables. You can see what 
// constraints are referencing a table by issuing the following 
// command:
// SELECT * FROM USER_CONSTRAINTS WHERE TABLE_NAME = "tabnam";

10:07:48 SQL> alter table mapevent disable primary key cascade;

Table altered.

10:07:52 SQL> truncate table mapevent;

Table truncated.

10:07:57 SQL> alter table mapevent enable primary key;

Table altered.