问异常块不能在DBMS_CLOUD PL/SQL中工作

EN

SQL> begin
  2  dbms_cloud.create_external_table(
  3  table_name => 'ext_table',
  4  credential_name =>'cred_name',
  5  file_uri_list => 'https://.../invalidBucket/...',
  6  column_list => 'name varchar2(20), age number',
  7  format => json_object('type' value 'CSV'));
  8  exception
  9      when others then
 10              dbms_output.put_line('Failed!');
 11  
 12  end;
 13  /

PL/SQL procedure successfully completed.

SQL> 
SQL> select * from ext_table order by 1;
select * from ext_table order by 1
*
ERROR at line 1:
ORA-29913: error in executing ODCIEXTTABLEOPEN callout
ORA-20400: Request failed with status HTTP 400 -
https.*
Error response - <?xml version="1.0" encoding="UTF-8"?>
<Error><Code>InvalidBucketName</Code><Message>The specified bucket is not
valid.</Message><BucketName></BucketName><RequestId>RequestID</RequestId>
<HostId>HostID</HostId></Error>
ORA-06512
ORA-06512
ORA-06512

SQL> declare
  2  c_name varchar2(20) := 'a';
  3  begin
  4  select name into c_name from ext_table order by 1;
  5  exception
  6      when others then
  7              dbms_output.put_line('Failed from select');
  8  end;
  9  /

PL/SQL procedure successfully completed.