关于在procedure中调用dbms_lock的package

Procedure created.

SQL> show user;
USER is "SYS"
SQL> conn xiaoyu/xiaoyu
Connected.
SQL> create or replace procedure proc01 as
2 begin
3 dbms_lock.sleep(10);
4 end;
5 /

Warning: Procedure created with compilation errors.

SQL> show errors;
Errors for PROCEDURE PROC01:

LINE/COL ERROR
-------- -----------------------------------------------------------------
3/1 PL/SQL: Statement ignored
3/1 PLS-00201: identifier 'DBMS_LOCK' must be declared
SQL> conn / as sysdba
Connected.

这里用静态sql调用dbms_lock的package时，oracle报出了无法识别该package，这里需要单独授权这个package给用户，这个需要特别注意，因为正常的匿名块程序中我们是可以调用的，但是procedure中则不行了。
SQL> grant execute on sys.dbms_lock to xiaoyu;

Grant succeeded.

SQL> conn xiaoyu/xiaoyu
Connected.
SQL> create or replace procedure proc01 as
2 begin
3 dbms_lock.sleep(10);
4 end;
5 /

Procedure created.

但是这里并不是说所有的dbms开头的package下的对象都不能在procedure或者function中调用，比如dbms_stats的package在不单独授权的情况下就能够正常调用。

SQL> create or replace procedure proc03 as
2 begin
3 dbms_stats.gather_table_stats(ownname=>'SYS',tabname=>'T_DYNAMIC01');
4 end;
5 /

Procedure created.

这里我们想想动态sql能否实现了：
SQL> revoke execute on sys.dbms_lock from xiaoyu;

Revoke succeeded.

SQL> create or replace procedure proc01 as
2 begin
3 execute immediate 'dbms_lock.sleep(10)';
4 end;
5 /

Procedure created.

SQL> exec proc01;
BEGIN proc01; END;

*
ERROR at line 1:
ORA-00900: invalid SQL statement
ORA-06512: at "SYS.PROC01", line 3
ORA-06512: at line 1

这里来看动态sql执行的时候出现了问题，oracle报出了在第三行出现了无效的语句，动态sql相比静态sql可以解决一些静态sql无法实现的问题，比如参数的不确定性造成没办法评估程序的具体操作，再比如在存储过程或者匿名块中实现ddl语句。

如下动态sql解决在procedure中实现ddl的示例：
SQL> create or replace procedure proc02 as
2 begin
3 create table t_dynamic01 as select * from dual;
4 end;
5 /

Warning: Procedure created with compilation errors.

SQL> show errors;
Errors for PROCEDURE PROC02:

LINE/COL ERROR
-------- -----------------------------------------------------------------
3/1 PLS-00103: Encountered the symbol "CREATE" when expecting one of
the following:
begin case declare exit for goto if loop mod null pragma
raise return select update while with
<<
close current delete fetch lock insert open rollback
savepoint set sql execute commit forall merge pipe

SQL> create or replace procedure proc02 as
2 begin
3 execute immediate 'create table t_dynamic01 as select * from dual';
4 end;
5 /

Procedure created.

SQL> exec proc02;

PL/SQL procedure successfully completed.

SQL> select * from t_dynamic01;