在oracle中什么算ddl語句

對於create我們知道這是一個ddl語句，另外還有一些操作，其實對於數據庫來說也是ddl操作。當發生ddl操作時，有關對象的sql語句都會出現重新解析的情況，所以在生產環境下要注意此類操作。

1.在表上創建對象、在線重建索引

SQL> create table dayu0718 as select * from dba_objects;

Table created.

SQL> commit;

Commit complete.

SQL> alter session set nls_date_format='yyyymmdd hh24:mi';

Session altered.


SQL> select last_ddl_time from dba_objects where object_name='DAYU0718';

LAST_DDL_TIME
--------------
20180718 13:37


SQL> create index dayu0718_ind on dayu0718(object_id);

Index created.

SQL> select last_ddl_time from dba_objects where object_name='DAYU0718';

LAST_DDL_TIME
--------------
20180718 13:39


SQL> alter index dayu0718_ind rebuild online;

Index altered.

SQL>  select last_ddl_time from dba_objects where object_name='DAYU0718';

LAST_DDL_TIME
--------------
20180718 13:41

2.添加、刪除列

SQL> alter table DAYU0718 add column_new varchar(30);

Table altered.

SQL> select last_ddl_time from dba_objects where object_name='DAYU0718';

LAST_DDL_TIME
--------------
20180718 13:50


SQL> alter table DAYU0718 drop column column_new;

Table altered.

SQL>  select last_ddl_time from dba_objects where object_name='DAYU0718';

LAST_DDL_TIME
--------------
20180718 13:51

3.增加、調整約束

SQL> alter table dayu0718 add constraint pk_object_id primary key(object_id);

Table altered.

SQL>  select last_ddl_time from dba_objects where object_name='DAYU0718';

LAST_DDL_TIME
--------------
20180718 14:06

4.若表為分區表，truncate分區表