RE: perplexing plan?

From: Koivu, Lisa <lisa.koivu_at_efairfield.com>
Date: Fri, 05 Oct 2001 10:36:34 -0700
Message-ID: <F001.003A3BCB.20011005103039@fatcity.com>

Remco, why do you say don't use hints unless you really have to? 

Lisa Koivu
Oracle Database Administrator
Fairfield Resorts, Inc.
954-935-4117

-----Original Message-----

From:   Doug C [SMTP:dcowles_at_i84.net]
Sent:   Friday, October 05, 2001 1:51 PM
To:     Multiple recipients of list ORACLE-L

Subject:        Re: perplexing plan?

This was a vendor designed query.   To my knowlege - it is complete.   As to the performance problem - it was apparently caused by a "tool" that was suppossed to analyze statistics on the some of the associated tables and didn't.   It was rectified, and now the query screams.   I'm am somewhat anxious to see the new trace of it however.  I'll probably post it shortly.

On Fri, 05 Oct 2001 08:20:21 -0800, you wrote:

>Doug,
>
>Sorting is caused by the "distinct", and is probably the cause of your
>performance problem. Try to limit the sorting to a minimal number of rows,
>e.g. by creating a temp table containing all (including the multiple copies)
>rows and then select the distinct values of that table. You could also try :
>select distinct * from (select ......) to replace the select distinct.
>
>Another tip: don't you hints unless you really have to ...
>
>HTH,  Remco
>
>-----Oorspronkelijk bericht-----
>Van: Doug C [mailto:dcowles_at_i84.net]
>Verzonden: vrijdag 5 oktober 2001 16:30
>Aan: Multiple recipients of list ORACLE-L
>Onderwerp: perplexing plan?
>
>
>I'm a little perplexed by this query and it's associated plan.  It's also a
>big
>performance problem.  The problem is the 35 million row table clearly.  But
>looking at the plan at the bottom, I'm not sure where the sorting is going
>on.
>Would anyone say the index full scan on the 35 million row table is being
>sorted?  Or does it look more like it's being fed to a nested loops query?
>
>Thanks,
>Doug
>
>SELECT /*+ ORDERED INDEX(S_ S15_IX1) INDEX(BUS_FID F15_UK1) INDEX(STREET
>A15_IX1) */  SDE.STREET.CFCC,  SDE.STREET.BUS_FID  ,S_.eminx,S_.eminy,
>  S_.emaxx,S_.emaxy, BUS_FID.fid,BUS_FID.numofpts,BUS_FID.entity,
>  BUS_FID.points,BUS_FID.rowid
>FROM
> (SELECT /*+ INDEX(SP_ S15_IX1) */ DISTINCT sp_fid,eminx,eminy,emaxx,emaxy
>  FROM SDE.S15 SP_   WHERE SP_.gx >= :1 AND SP_.gx <= :2 AND SP_.gy >= :3
>  AND SP_.gy <= :4 AND SP_.eminx <= :5 AND SP_.eminy <= :6 AND SP_.emaxx >=
>:7
>  AND SP_.emaxy >= :8) S_
>,  SDE.STREET
> , SDE.F15 BUS_FID
>WHERE S_.sp_fid =  BUS_FID.fid
>AND S_.sp_fid = SDE.STREET.BUS_FID
>
>
>call     count       cpu    elapsed       disk      query    current
>rows
>------- ------  -------- ---------- ---------- ---------- ----------
>----------
>Parse        1      0.00       0.00          0          0          0
>0
>Execute      1      0.00       0.00          0          0          0
>0
>Fetch       45    473.15     475.04     223532   66153503          0
>4494
>------- ------  -------- ---------- ---------- ---------- ----------
>----------
>total       47    473.15     475.04     223532   66153503          0
>4494
>
>Misses in library cache during parse: 1
>Optimizer goal: CHOOSE
>Parsing user id: 20
>
>Rows     Row Source Operation
>-------  ---------------------------------------------------
>   4494  HASH JOIN
>   4494    NESTED LOOPS
>   4495      VIEW
>   4495         SORT UNIQUE
>   4817           INDEX RANGE SCAN (object id 7356)
>   4494      TABLE ACCESS BY INDEX ROWID STREET
>   8988            INDEX UNIQUE SCAN (object id 7355)
>33065402  TABLE ACCESS BY INDEX ROWID F15
>33065403        INDEX FULL SCAN (object id 7283)
>--
>Please see the official ORACLE-L FAQ: http://www.orafaq.com
>--
>Author: Doug C
>  INET: dcowles_at_i84.net
>
>Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
>San Diego, California        -- Public Internet access / Mailing Lists
>--------------------------------------------------------------------
>To REMOVE yourself from this mailing list, send an E-Mail message
>to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
>the message BODY, include a line containing: UNSUB ORACLE-L
>(or the name of mailing list you want to be removed from).  You may
>also send the HELP command for other information (like subscribing).
>--
>Please see the official ORACLE-L FAQ: http://www.orafaq.com

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Doug C
  INET: dcowles_at_i84.net


Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).

Received on Fri Oct 05 2001 - 12:36:34 CDT