PL/SQL 0.几秒出结果,SQL效率一定高吗？

今天开发问我一个问题,PL/SQL很快出结果了,为什么应用还是很慢
create index F_AGT_SAVB_ACCTINFO_H_idx4 on F_AGT_SAVB_ACCTINFO_H

(agmt_id,last_trans_date,acct_bal,start_dt,end_dt,acct_status);

SQL>  select  agmt_id, max(last_trans_date) last_trans_date, sum(acct_bal) acct_bal
                      from dwf.F_AGT_SAVB_ACCTINFO_H
                     where start_dt <= to_date('2014-03-31', 'YYYY-MM-DD')
                       and end_dt > to_date('2014-03-31', 'YYYY-MM-DD')
                       and acct_status <> '1'
                       group by  agmt_id;  2    3    4    5    6  

596497 rows selected.


Execution Plan
----------------------------------------------------------
Plan hash value: 1288393334

------------------------------------------------------------------------------------------------------------
| Id  | Operation	      | Name			   | Rows  | Bytes |TempSpc| Cost (%CPU)| Time	   |
------------------------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT      | 			   |   698K|	34M|	   | 44078   (1)| 00:08:49 |
|   1 |  HASH GROUP BY	      | 			   |   698K|	34M|	65M| 44078   (1)| 00:08:49 |
|*  2 |   INDEX FAST FULL SCAN| F_AGT_SAVB_ACCTINFO_H_IDX4 |  1010K|	50M|	   | 33677   (1)| 00:06:45 |
------------------------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   2 - filter("END_DT">TO_DATE(' 2014-03-31 00:00:00', 'syyyy-mm-dd hh24:mi:ss') AND
	      "ACCT_STATUS"<>'1' AND "START_DT"<=TO_DATE(' 2014-03-31 00:00:00', 'syyyy-mm-dd hh24:mi:ss'))


Statistics
----------------------------------------------------------
	  0  recursive calls
	  0  db block gets
     124565  consistent gets
	  0  physical reads
	  0  redo size
   27208221  bytes sent via SQL*Net to client
     437946  bytes received via SQL*Net from client
      39768  SQL*Net roundtrips to/from client
	  0  sorts (memory)
	  0  sorts (disk)
     596497  rows processed

走INDEX FAST FULL SCAN 需要3S出结果


走INDEX FULL SCAN :
create index F_AGT_SAVB_ACCTINFO_H_idx4 on F_AGT_SAVB_ACCTINFO_H(agmt_id,last_trans_date,acct_bal);


Execution Plan
----------------------------------------------------------
Plan hash value: 2644626439

-----------------------------------------------------------------------------------------------------------
| Id  | Operation		     | Name			  | Rows  | Bytes | Cost (%CPU)| Time	  |
-----------------------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT	     |				  |   698K|    34M|    14M  (1)| 47:22:11 |
|   1 |  SORT GROUP BY NOSORT	     |				  |   698K|    34M|    14M  (1)| 47:22:11 |
|*  2 |   TABLE ACCESS BY INDEX ROWID| F_AGT_SAVB_ACCTINFO_H	  |  1010K|    50M|    14M  (1)| 47:22:11 |
|   3 |    INDEX FULL SCAN	     | F_AGT_SAVB_ACCTINFO_H_IDX4 |    14M|	  | 88373   (1)| 00:17:41 |
-----------------------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   2 - filter("END_DT">TO_DATE(' 2014-03-31 00:00:00', 'syyyy-mm-dd hh24:mi:ss') AND
	      "ACCT_STATUS"<>'1' AND "START_DT"<=TO_DATE(' 2014-03-31 00:00:00', 'syyyy-mm-dd hh24:mi:ss'))


Statistics
----------------------------------------------------------
	  1  recursive calls
	  0  db block gets
   14247288  consistent gets
    1189251  physical reads
	  0  redo size
   28157922  bytes sent via SQL*Net to client
     437946  bytes received via SQL*Net from client
      39768  SQL*Net roundtrips to/from client
	  0  sorts (memory)
	  0  sorts (disk)
     596497  rows processed


 select /*+ index(F_AGT_SAVB_ACCTINFO_H F_AGT_SAVB_ACCTINFO_H_idx4)*/ agmt_id, max(last_trans_date) last_trans_date, 

sum(acct_bal) acct_bal
                      from dwf.F_AGT_SAVB_ACCTINFO_H
                     where start_dt <= to_date('2014-03-31', 'YYYY-MM-DD')
                       and end_dt > to_date('2014-03-31', 'YYYY-MM-DD')
                       and acct_status <> '1'
                       group by  agmt_id;

但是这个SQL 出结果确是0.几秒

总结:PL/SQL这个工具坑爹,出结果快慢和SQL块慢没必然联系