谈谈oracle中的锁

SQL> create user dev identified by oracle;
g
User created.

SQL>grant dba to dev;

Grant succeeded.

SQL> !clear

SQL> create table father as  select * from scott.dept;

Table created.

SQL> create table childen as  select * from scott.emp;

Table created.

SQL> alter table father add  constraint pk_deptno primary key (deptno);

Table altered.

SQL> alter table childen add  constraint fk_deptno foreign key (deptno) references father(deptno);

Table altered.

SQL> insert into father  values(50,'beijing','china');

1 row created.

SQL> col object_id for 99999
SQL> col object_name for a10
SQL> select  lock1.object_id,obj.object_name,lock1.session_id,lock1.locked_mode from  v$locked_object lock1 ,dba_objects obj where lock1.session_id=159 and  lock1.object_id=obj.object_id;

no rows selected

SQL> select userenv('sid') from dual;

USERENV('SID')
--------------
             1

SQL> select  lock1.object_id,obj.object_name,lock1.session_id,lock1.locked_mode from  v$locked_object lock1 ,dba_objects obj where lock1.session_id=1 and  lock1.object_id=obj.object_id;

OBJECT_ID OBJECT_NAM SESSION_ID LOCKED_MODE
--------- ---------- ---------- -----------
    74604 FATHER              1           3
    74605 CHILDEN             1           3