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Re: RE: URGENT : sql*loader performance problem on partionned table

From: <rgaffuri_at_cox.net>
Date: Wed, 03 Sep 2003 06:14:26 -0800
Message-ID: <F001.005CEA2E.20030903061426@fatcity.com> 





    
  
  1.   by 'filling' are you doing inserts also? I see a 'FOR UPDATE' statement which implies that you are doing updates from with in a cursor. 
  
  2.   How many indexes do you have on this table?
  
  3.   Is anything else running at the same time? 
  
  4.   Are you doing your DML from with in a cursor. This is very slow. Try to do it all in SQL. 
  
  5.   Consider changing your not exists to 
Where NOT IN (SELECT /*+ hash_aj */ ...)
That can be faster if your sub-query is significantly less costly than your your outer query(its the opposite for exists). Wont necessarily help in your case. 
You can also eliminate the join with the 'in'. This can improve performance as well. 






Please post a subset of your batch script. Please format it so its readable. Ill look at it. Also please post how many rows are in each table. 



Ill see if I can find anything. I think the two locks on the same object are locks on seperate partitions. Not sure. 


> 

> From: "NGUYEN Philippe (Cetelem)" <philippe.nguyen_at_cetelem.fr>

> Date: 2003/09/03 Wed AM 09:59:27 EDT

> To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>

> Subject: RE: URGENT : sql*loader performance problem on partionned table

> 

> thank U Dennis,

> 

> I use local index, 

> the script is still running (2hours now! instead of 10-20 min) and here is

> the statement  in question (the script who used non-partionned table is

> already ended)

> 

> SELECT NULL


>     FROM hrel_fusion

>     WHERE cod_rel = :b1

>       AND dat_rel = :b2

>       AND NOT EXISTS (SELECT NULL


>                       FROM primedi_enr2_temp_fusion

>                       WHERE primedi_enr2_temp_fusion.nodos_or = 

>                             hrel_fusion.nodos_or

>                         AND primedi_enr2_temp_fusion.code_logis = 

>                             hrel_fusion.cod_rel

>                         AND primedi_enr2_temp_fusion.date_logis = 

>                             hrel_fusion.dat_rel)

>     FOR UPDATE


> 

> 

> The explain plan show that hrel_fusion table is ACCESS BY LOCAL INDEX ROWID

> and primedi table used INDEX too.

> When I looking at lock tables it show me 2 session locked :

> 

> SQL> select session_id, oracle_username, object_name

>   2  from v$locked_object lo, dba_objects o

>   3  where lo.object_id = o.object_id

>   4  ;

> 

> SESSION_ID ORACLE_USERNAME                OBJECT_NAME


> ---------- ------------------------------

> ----------------------------------------------------------------------------

> ----

>          7 FICOM                          HREL_FUSION


>          7 FICOM                          HREL_FUSION


> 

> -Why are there 2 locks on this table even there only one session ?

> - Yesterday I did gather_statitic on this table and it worked fine (12 min),

> should I do this each day ?

> TIA


> Philippe

> 

> 

> 

> -----Message d'origine-----

> De : DENNIS WILLIAMS [mailto:DWILLIAMS_at_lifetouch.com]

> Envoyé : 02 September 2003 19:45

> À : Multiple recipients of list ORACLE-L

> Objet : RE: URGENT : sql*loader performance problem on partionned table

> 

> 

> Philippe

>      You aren't providing many details on which to base some guesses.

> However, your statement "brand new disks" implies that you are adding

> additional partitions to an existing table. Then, your statement "should I

> drop indexes" implies that you have indexes on the partitioned table,

> possibly global indexes. If you are continuing to grow a partitioned (or

> non-partitioned) table than has indexes, then the load time will increase

> because Oracle must integrate each new entry into the index, which will take

> more time as the index grows. Take a look at local indexes. If I not

> understood your situation correctly, please clarify your situation further.

> 

> 

> 

> Dennis Williams 

> DBA, 80%OCP, 100% DBA 


> Lifetouch, Inc. 

> dwilliams_at_lifetouch.com 

> 

> -----Original Message-----

> Sent: Tuesday, September 02, 2003 12:14 PM

> To: Multiple recipients of list ORACLE-L

> 

> 

> 

> Hi gurus, 

> we have two daily loads that one after the other. 

> The first fill up a non partitionned table and the second do the same into a

> partitionned table. 

> First times the second load ran very quickly : 1 min instead of 5 min (non

> partitionnned table). 

> But now since few days, the partitionned table filling take more than 1-2

> hours ! yesterday it took 14 hours !!!! 

> Any one has any clue ? 

> - Tablespaces for partitionned table used brand new separate disks 

> - Does it come from indexes ? should I drop them first ? 

> 

> Thankx in advance! 

> 

> 

> -- 

> Please see the official ORACLE-L FAQ: http://www.orafaq.net

> -- 

> Author: DENNIS WILLIAMS

>   INET: DWILLIAMS_at_LIFETOUCH.COM


> 

> 

> 









RE: URGENT : sql*loader performance problem on partionned table




thank U Dennis,




I use local index, 

the script is still running (2hours now! instead of 10-20 min) and here is the statement  in question (the script who used non-partionned table is already ended)



SELECT NULL

    FROM hrel_fusion

    WHERE cod_rel = :b1

      AND dat_rel = :b2

      AND NOT EXISTS (SELECT NULL

                      FROM primedi_enr2_temp_fusion

                      WHERE primedi_enr2_temp_fusion.nodos_or = 

                            hrel_fusion.nodos_or

                        AND primedi_enr2_temp_fusion.code_logis = 

                            hrel_fusion.cod_rel

                        AND primedi_enr2_temp_fusion.date_logis = 

                            hrel_fusion.dat_rel)

    FOR UPDATE






The explain plan show that hrel_fusion table is ACCESS BY LOCAL INDEX ROWID and primedi table used INDEX too.

When I looking at lock tables it show me 2 session locked :




SQL> select session_id, oracle_username, object_name

  2  from v$locked_object lo, dba_objects o

  3  where lo.object_id = o.object_id

  4  ;




SESSION_ID ORACLE_USERNAME                OBJECT_NAME

---------- ------------------------------ --------------------------------------------------------------------------------



         7 FICOM                          HREL_FUSION

         7 FICOM                          HREL_FUSION




-Why are there 2 locks on this table even there only one session ?

- Yesterday I did gather_statitic on this table and it worked fine (12 min), should I do this each day ?

TIA

Philippe








-----Message d'origine-----

De : DENNIS WILLIAMS [mailto:DWILLIAMS@lifetouch.com]

Envoyé : 02 September 2003 19:45

À : Multiple recipients of list ORACLE-L

Objet : RE: URGENT : sql*loader performance problem on partionned table






Philippe

     You aren't providing many details on which to base some guesses.

However, your statement "brand new disks" implies that you are adding

additional partitions to an existing table. Then, your statement "should I

drop indexes" implies that you have indexes on the partitioned table,

possibly global indexes. If you are continuing to grow a partitioned (or

non-partitioned) table than has indexes, then the load time will increase

because Oracle must integrate each new entry into the index, which will take

more time as the index grows. Take a look at local indexes. If I not

understood your situation correctly, please clarify your situation further.








Dennis Williams 

DBA, 80%OCP, 100% DBA 

Lifetouch, Inc. 

dwilliams@lifetouch.com 




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

Sent: Tuesday, September 02, 2003 12:14 PM

To: Multiple recipients of list ORACLE-L








Hi gurus, 

we have two daily loads that one after the other. 

The first fill up a non partitionned table and the second do the same into a

partitionned table. 

First times the second load ran very quickly : 1 min instead of 5 min (non

partitionnned table). 

But now since few days, the partitionned table filling take more than 1-2

hours ! yesterday it took 14 hours !!!! 

Any one has any clue ? 

- Tablespaces for partitionned table used brand new separate disks 

- Does it come from indexes ? should I drop them first ? 




Thankx in advance! 






-- 

Please see the official ORACLE-L FAQ: http://www.orafaq.net

-- 

Author: DENNIS WILLIAMS

  INET: DWILLIAMS@LIFETOUCH.COM








-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: <rgaffuri_at_cox.net
  INET: rgaffuri_at_cox.net

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Received on Wed Sep 03 2003 - 09:14:26 CDT












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