SQL排序吃大量的内存和CPU，但不走索引

大家好，我有一条SQL语句在执行过程之中吃CPU非常严重，我检测发现是因为大量sort引起的。并我先使用runstats更新统计信息并且使用db2advis工具来添加对应的索引。但是发现还是不起作用。还是有大量的排序而且排序也会益处，我的sortheap设置为automaitc，并且AIX机器的内存还有大量的多余。麻烦大家看一下这个SQL语句到底是怎么一个情况如何优化。下面是该SQL语句
Number of executions               = 787  
Number of compilations             = 1  
Worst preparation time (ms)        = 6  
Best preparation time (ms)         = 6  
Internal rows deleted              = 0  
Internal rows inserted             = 0
Rows read                          = 133804156  
Internal rows updated              = 0  
Rows written                       = 200671179  
Statement sorts                    = 779  
Statement sort overflows           = 779  
Total sort time                    = 229421  
Buffer pool data logical reads     = 67260418
Buffer pool data physical reads    = 0  
Buffer pool temporary data logical reads   = 144015288  
Buffer pool temporary data physical reads  = 0  
Buffer pool index logical reads    = 26486
Buffer pool index physical reads   = 0  
Buffer pool temporary index logical reads  = 0  
Buffer pool temporary index physical reads = 0  
Buffer pool xda logical reads      = 0  
Buffer pool xda physical reads     = 0  
Buffer pool temporary xda logical reads    = 0  
Buffer pool temporary xda physical reads   = 0  
Total execution time (sec.microsec)= 704.447443  
Total user cpu time (sec.microsec) = 350.010853  
Total system cpu time (sec.microsec)= 2.192628  
Total statistic fabrication time (milliseconds) = 0  
Total synchronous runstats time  (milliseconds) = 0  
Statement text                     = SELECT WIID,SYSTEM_ID,TEMPLATE_ID,TEMPLATE_VER,APPLY_ID,APPLY_TITLE,STATE,CREATE_TIME,FINISH_TIME,PIID,NODE_ID,NODE_NAME,NODE_TYPE,OWNER,LASTMODIFIED,HANDLE_URL,HANDLER,PWID,PROVINCE_ID,TEMPLATE_ALIAS,MAP_WIID,ORIGINAL_OWNER,GRANT_TYPE FROM mss.UNIFLOW_WORKITEM WHERE SYSTEM_ID=? AND TEMPLATE_ALIAS IN(?) AND (OWNER IN(?) OR HANDLER IN(?)) AND STATE IN(?) ORDER BY CREATE_TIME DESC

还有对应的执行计划
******************** DYNAMIC ***************************************

==================== STATEMENT ==========================================

        Isolation Level          = Cursor Stability
        Blocking                 = Block Unambiguous Cursors
        Query Optimization Class = 5

        Partition Parallel       = No
        Intra-Partition Parallel = No

        SQL Path                 = "SYSIBM", "SYSFUN", "SYSPROC", "SYSIBMADM",
                                   "DB2INST1"


Statement:
  
  SELECT WIID, SYSTEM_ID, TEMPLATE_ID, TEMPLATE_VER, APPLY_ID,
          APPLY_TITLE, STATE, CREATE_TIME, FINISH_TIME, PIID, NODE_ID,
          NODE_NAME, NODE_TYPE, OWNER, LASTMODIFIED, HANDLE_URL,
          HANDLER, PWID, PROVINCE_ID, MAP_WIID, ORIGINAL_OWNER,
          GRANT_TYPE
  FROM mss.UNIFLOW_WORKITEM
  WHERE SYSTEM_ID='FinancialAssist' AND TEMPLATE_ALIAS='1301-AC' AND
          (OWNER IN('puhuiyan' )OR HANDLER IN('puhuiyan' ))AND STATE
          IN(2, 1)
  ORDER BY CREATE_TIME DESC


Section Code Page = 1208

Estimated Cost = 20.011341
Estimated Cardinality = 0.392774

Access Table Name = MSS.UNIFLOW_WORKITEM  ID = -6,-32767
|  Index Scan:  Name = MSS.TEST4  ID = 20
|  |  Regular Index (Not Clustered)
|  |  Index Columns:
|  |  |  1: TEMPLATE_ALIAS (Ascending)
|  |  |  2: SYSTEM_ID (Ascending)
|  |  |  3: HANDLER (Ascending)
|  |  |  4: OWNER (Ascending)
|  #Columns = 22
|  Data-Partitioned Table
|  Avoid Locking Committed Data
|  All data partitions will be accessed
|  Evaluate Predicates Before Locking for Committed Key
|  #Key Columns = 2
|  |  Start Key: Inclusive Value
|  |  |  |  1: '1301-AC'
|  |  |  |  2: 'FinancialAssist'
|  |  Stop Key: Inclusive Value
|  |  |  |  1: '1301-AC'
|  |  |  |  2: 'FinancialAssist'
|  Data Prefetch: None
|  Index Prefetch: None
|  Lock Intents
|  |  Table: Intent Share
|  |  Row  : Next Key Share
|  Sargable Index Predicate(s)
|  |  #Predicates = 2
|  Sargable Predicate(s)
|  |  #Predicates = 1
|  |  Insert Into Sorted Temp Table  ID = t1
|  |  |  #Columns = 22
|  |  |  #Sort Key Columns = 1
|  |  |  |  Key 1: CREATE_TIME (Descending)
|  |  |  Sortheap Allocation Parameters:
|  |  |  |  #Rows     = 1.000000
|  |  |  |  Row Width = 512
|  |  |  Piped
Sorted Temp Table Completion  ID = t1
Access Temp Table  ID = t1
|  #Columns = 22
|  Relation Scan
|  |  Prefetch: Eligible
|  Sargable Predicate(s)
|  |  Return Data to Application
|  |  |  #Columns = 22
Return Data Completion

End of section


Optimizer Plan:

               Rows   
             Operator
               (ID)   
               Cost   
                     
             0.392774
              RETURN  
               ( 1)   
             20.0113  
                |     
             0.392774
              TBSCAN  
               ( 2)   
             20.0113  
                |     
             0.392774
               SORT   
               ( 3)   
              20.011  
                |     
             0.392774
              FETCH   
               ( 4)   
             20.0103  
            /        
     0.423429   3.6234e+06   
      IXSCAN   Table:        
       ( 5)    <65530,32769>
     16.8065  
        |         
      117328      
Index:           
<65530,32769,20>收起