增加表字段且按顺序数字填充

文档课题：增加表字段且按顺序数字填充.
数据库：oracle 11.2.0.4 64位
应用场景：表与表之间连接时，很多时候需要增加一个不重复的数值字段作为连接条件.
以下测试过程.
SQL> desc aud$_ts;
Name            Type           Nullable Default Comments 
--------------- -------------- -------- ------- -------- 
SESSIONID       NUMBER                                   
ENTRYID         NUMBER                                   
STATEMENT       NUMBER                                   
TIMESTAMP#      DATE           Y                         
USERID          VARCHAR2(30)   Y                         
USERHOST        VARCHAR2(128)  Y                         
TERMINAL        VARCHAR2(255)  Y                         
ACTION#         NUMBER                                   
RETURNCODE      NUMBER                                   
OBJ$CREATOR     VARCHAR2(30)   Y                         
OBJ$NAME        VARCHAR2(128)  Y                         
AUTH$PRIVILEGES VARCHAR2(16)   Y                         
AUTH$GRANTEE    VARCHAR2(30)   Y                         
NEW$OWNER       VARCHAR2(30)   Y                         
NEW$NAME        VARCHAR2(128)  Y                         
SES$ACTIONS     VARCHAR2(19)   Y                         
SES$TID         NUMBER         Y                         
LOGOFF$LREAD    NUMBER         Y                         
LOGOFF$PREAD    NUMBER         Y                         
LOGOFF$LWRITE   NUMBER         Y                         
LOGOFF$DEAD     NUMBER         Y                         
LOGOFF$TIME     DATE           Y                         
COMMENT$TEXT    VARCHAR2(4000) Y                         
CLIENTID        VARCHAR2(64)   Y                         
SPARE1          VARCHAR2(255)  Y                         
SPARE2          NUMBER         Y                         
OBJ$LABEL       RAW(255)       Y                         
SES$LABEL       RAW(255)       Y                         
PRIV$USED       NUMBER         Y                         
SESSIONCPU      NUMBER         Y                         
NTIMESTAMP#     TIMESTAMP(6)   Y                         
PROXY$SID       NUMBER         Y                         
USER$GUID       VARCHAR2(32)   Y                         
INSTANCE#       NUMBER         Y                         
PROCESS#        VARCHAR2(16)   Y                         
XID             RAW(8)         Y                         
AUDITID         VARCHAR2(64)   Y                         
SCN             NUMBER         Y                         
DBID            NUMBER         Y                         
SQLBIND         CLOB           Y                         
SQLTEXT         CLOB           Y                         
OBJ$EDITION     VARCHAR2(30)   Y                         

SQL> create table sort as select * from aud$_ts where rownum<101;

Table created.

Elapsed: 00:00:00.16

SQL> alter table sort add idnum integer;

Table altered.

--按sessionid排序，将idnum字段用数值填充.
merge into sort t
using (select rowid as rid, row_number() over (order by sessionid) as rn from sort) s
   on (s.rid = t.rowid)
when matched then update set idnum = rn;

说明：以上测试填充的是不重复的数字，可以满足笔者需求，至于要按顺序填充数字后续在更新.