11.2.0.3 下尝试使用11g health monitor新特性时出现了ORA-00604、ORA-01427， 查询MOS发现 (Bug 12385172: ORA-01427 WHEN EXECUTING DBMS_HM.RUN_CHECK)，当 DB中存在case when then的function index时会触发该BUG:   
SQL> select * from v$version;

BANNER
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Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
PL/SQL Release 11.2.0.3.0 - Production
CORE    11.2.0.3.0      Production
TNS for Linux: Version 11.2.0.3.0 - Production
NLSRTL Version 11.2.0.3.0 - Production

SQL> select * from global_name;

GLOBAL_NAME
--------------------------------------------------------------------------------
www.oracledatabase12g.com

SQL> exec dbms_hm.run_check('Dictionary Integrity Check','check-2');
BEGIN dbms_hm.run_check('Dictionary Integrity Check','check-2'); END;

*
ERROR at line 1:
ORA-00604: error occurred at recursive SQL level 1
ORA-01427: single-row subquery returns more than one row
ORA-06512: at "SYS.DBMS_HM", line 191
ORA-06512: at line 1
    可以通过以下脚本找出 DB中case when then类型的函数索引：     
-- Determine DDL statements (note: this will take a while to return results!)

 set long 100000

 exec dbms_metadata.set_transform_param(dbms_metadata.session_transform,'PRETTY',true);
 exec dbms_metadata.set_transform_param(dbms_metadata.session_transform,'TABLESPACE',false);
 exec dbms_metadata.set_transform_param(dbms_metadata.session_transform,'SEGMENT_ATTRIBUTES',false);
 exec dbms_metadata.set_transform_param(dbms_metadata.session_transform,'STORAGE',false);

 -- Checking the DDL statement
 col DDL form a100 word_wrapped
 select dbms_metadata.get_ddl(RTRIM(UPPER(object_type)),