Oracle ROWID

SQL> set autotrace off

SQL> select rowid from hr.employees;

ROWID

-----------

AAAMg3AAFAAAABYABa

AAAMg3AAFAAAABYAAg

AAAMg3AAFAAAABYAAp

AAAMg3AAFAAAABYABf

AAAMg3AAFAAAABYAAG

AAAMg3AAFAAAABUAAI

AAAMg3AAFAAAABYABH

AAAMg3AAFAAAABYABQ

...

107 rows selected.

rowid格式如下：
AAAPW1--->数据对象编号
AAL--->文件编号
AAAAA1--->块编号
AAA---->行号 

通过dbms_rowid包，直接得到具体的rowid包含的信息

SQL> select dbms_rowid.rowid_object(rowid)   object_id,

  2  dbms_rowid.rowid_relative_fno(rowid)  file_id,

  3  dbms_rowid.rowid_block_number(rowid)  block_id,

  4  dbms_rowid.rowid_row_number(rowid)  num

  5  from scott.dept;

 OBJECT_ID    FILE_ID   BLOCK_ID        NUM

---------- ---------- ---------- ----------

     51146          4         16          0

     51146          4         16          1

     51146          4         16          2

     51146          4         16          3

知道object_id,查找具体的信息

SQL> select OBJECT_NAME from  dba_objects  where OBJECT_ID=51146; 

OBJECT_NAME

----------------

DEPT

知道file_id，查找具体的信息

SQL>select name,file#,ts# from v$datafile;