Oracle 错误消息中的行号与源行不匹配

ERROR at line 1:
ORA-06533: Subscript beyond count 
ORA-06512: at line 144 
ORA-06512: at line 2958 

declare

type log_entry is record (stamp timestamp(3),
                          sevlvl varchar2(32),
                          message varchar2(1024));

type sql_log_buffer is varray(100) of log_entry;

log_buffer sql_log_buffer := sql_log_buffer();

procedure test is
begin
    log_buffer(2).message = 'not extended';
end;

begin
    test();
end;
/

SQL> declare
  2
  3  type log_entry is record (stamp timestamp(3),
  4                            sevlvl varchar2(32),
  5                            message varchar2(1024));
  6
  7  type sql_log_buffer is varray(100) of log_entry;
  8
  9  log_buffer sql_log_buffer := sql_log_buffer();
 10
 11  procedure test is
 12  begin
 13      log_buffer(2).message = 'not extended';
 14  end;
 15
 16  begin
 17      test();
 18  end;
 19  /
    log_buffer(2).message = 'not extended';
                          *
ERROR at line 13:
ORA-06550: line 13, column 27:
PLS-00103: Encountered the symbol "=" when expecting one of the following:
:= . ( @ % ;
The symbol ":= was inserted before "=" to continue.

SQL> declare
  2
  3  type log_entry is record (stamp timestamp(3),
  4                            sevlvl varchar2(32),
  5                            message varchar2(1024));
  6
  7  type sql_log_buffer is varray(100) of log_entry;
  8
  9  log_buffer sql_log_buffer := sql_log_buffer();
 10
 11  procedure test is
 12  begin
 13      log_buffer(2).message := 'not extended';
 14  end;
 15
 16  begin
 17      test();
 18  end;
 19  /
declare
*
ERROR at line 1:
ORA-06533: Subscript beyond count
ORA-06512: at line 13
ORA-06512: at line 17