--查看当前用户的所有序列
select SEQUENCE_OWNER,SEQUENCE_NAME from dba_sequences where sequence_owner='用户名';


--查询当前用户的序列总数
select count(*) from dba_sequences where sequence_owner='用户名';


--示例：
select SEQUENCE_OWNER,SEQUENCE_NAME from dba_sequences 
where sequence_owner=’WGB;

select count(*) from dba_sequences where sequence_owner=’ WGB’;

SQL> select SEQUENCE_OWNER,SEQUENCE_NAME from dba_sequences
  2  where sequence_owner='WGB';

SEQUENCE_OWNER                 SEQUENCE_NAME
------------------------------ ------------------------------
WGB                            SEQ_FOR_TEST
WGB                            SEQ_WGB_ADMIN
WGB                            SEQ_WGB_COMMON
WGB                            SEQ_WGB_COMMONS
WGB                            SEQ_WGB_CONTACTOR
WGB                            SEQ_WGB_FACES
WGB                            SEQ_WGB_MEMBER
WGB                            SEQ_WGB_MESSAGE
WGB                            SEQ_WGB_MONEY_USER

已选择9行。

SQL> select count(*) from dba_sequences where sequence_owner='WGB';

  COUNT(*)
----------
         9

注意事项：

1.      必须以管理员身份登录；

2.      sequence_owner必须为大写，不管你的用户名是否大写。只有大写才能识别。

参考资料：

http://zhidao.baidu.com/question/140904731