oracle 根据rowid得到行所在的对象号，数据文件号，块号，行编号。
DBMS_ROWID.ROWID_OBJECT(ROWID) OBJECT_ID,
DBMS_ROWID.ROWID_RELATIVE_FNO(ROWID) FILE_ID,
DBMS_ROWID.ROWID_BLOCK_NUMBER(ROWID) BLOCK_ID,
DBMS_ROWID.ROWID_ROW_NUMBER(ROWID) NUM,