Re: High query cost but low execution time

  • From: Carlos Sierra <carlos.sierra.usa@xxxxxxxxx>
  • To: Amir.Hameed@xxxxxxxxx
  • Date: Wed, 18 Apr 2012 06:47:52 -0500

Amir,
I you want some analysis in this issue, I would suggest you install and use
SQLTXPLAIN (MOS 215187.1). You may want to use XTRACT or XECUTE methods. As
usual, I offer to review the output for a quick analysis.

Cheers -- Carlos



On Mon, Apr 16, 2012 at 1:54 PM, Hameed, Amir <Amir.Hameed@xxxxxxxxx> wrote:

> I have a statement which produces a high CBO cost but executes very
> quickly, as shown below. Based on the execution timings, is the cost figure
> a true representative of the response time? The DB version is 11.1.0.7.
> Thanks Amir call     count       cpu    elapsed       disk      query
>  current rows ------- ------  -------- ---------- ---------- ----------
> ---------- ---------- Parse        1      0.08       0.08          0
>   10          0 Execute      1      0.00       0.00          0          0
>        0 Fetch       54      0.82       0.79          0      18922
>  0 ------- ------  -------- ---------- ---------- ---------- ----------
> ---------- total       56      0.90       0.87          0      18932
>    0 Rows     Row Source Operation -------
>  ---------------------------------------------------     788  HASH GROUP BY
> (cr 017 pr=0 pw=0 time=7 us costs709 size 08608 card 224)    2633   NESTED
> LOOPS  (cr 932 pr=0 pw=0 timeW2 us costs403 size 08608 card 224)    2633
>  NESTED LOOPS  (cr 593 pr=0 pw=0 timeI5 us costY169 size 37920 card 224)
>  2633     NESTED LOOPS  (cr 36 pr=0 pw=0 time46 us cost0699 sizeh2752 card
> 224)    2633      NESTED LOOPS  (cr 79 pr=0 pw=0 time 6 us cost 19 
> size@1212card 329)       1       NESTED LOOPS  (cr  pr=0 pw=0 time=0 us cost  
> size
> card=1)       1        VIEW  VW_SQ_1 (cr  pr=0 pw=0 time=0 us cost=8 size=4
> card=1)       1         HASH UNIQUE (cr  pr=0 pw=0 time=0 us)       1
>    HASH JOIN  (cr  pr=0 pw=0 time=0 us cost=8 size5 card=1)       1
>   TABLE ACCESS BY INDEX ROWID XMAF_GEN_INT_PARAMS (cr=2 pr=0 pw=0 time=0 us
> cost=2 size' card=1)       1            INDEX RANGE SCAN PG_IDX1 (cr=1 pr=0
> pw=0 time=0 us cost=1 size=0 card=1)(object id 4486804)     215
> TABLE ACCESS FULL MTL_PARAMETERS (cr  pr=0 pw=0 time=4 us cost=5 size 20
> card!5)       1        TABLE ACCESS BY INDEX ROWID MTL_PARAMETERS (cr=2
> pr=0 pw=0 time=0 us cost=1 size=8 card=1)       1         INDEX UNIQUE SCAN
> MTL_PARAMETERS_U1 (cr=1 pr=0 pw=0 time=0 us cost=0 size=0 card=1)(object id
> 7243)    2633       TABLE ACCESS BY INDEX ROWID
> MTL_ONHAND_QUANTITIES_DETAIL 59 pr=0 pw=0 time 1 us cost 10 size"9264 card
>    2633        INDEX RANGE SCAN MTL_ONHAND_QUANTITIES_N8 (cr  pr=0 pw=0
> time  us costV size=0 card 329)(object id 3695328)    2633      TABLE
> ACCESS BY INDEX ROWID MTL_SYSTEM_ITEMS_B (cru57 pr=0 pw=0 time=0 us cost=2
> size  card=1)    2633       INDEX UNIQUE SCAN MTL_SYSTEM_ITEMS_B_U1 (crR18
> pr=0 pw=0 time=0 us cost=1 size=0 card=1)(object id 7343)    2633     TABLE
> ACCESS BY INDEX ROWID MTL_SYSTEM_ITEMS_B (cru57 pr=0 pw=0 time=0 us cost=2
> size2 card=1)    2633      INDEX UNIQUE SCAN MTL_SYSTEM_ITEMS_B_U1 (crR18
> pr=0 pw=0 time=0 us cost=1 size=0 card=1)(object id 7343)
> //www.freelists.org/webpage/oracle-l


--
//www.freelists.org/webpage/oracle-l


Other related posts: