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Re: A performance problem

From: <ryan_oracle_at_cox.net>
Date: Mon, 29 Dec 2003 09:09:25 -0800
Message-ID: <F001.005DB352.20031229090925@fatcity.com>


the sqlnet is a network issue. talk to your SAs. is the other database on a different server? work from there.

your big one is your read. could mean your SGA is too small. is anything else running at this time?

are you sure there is an equivalent amount of work to do? are you sure there isnt more data involved?

do you have a previous statspack report to compare it to? you also need to run a 10046 trace on the queries involved and see what they are doing.

maybe the plan changed do to a change in data or you dont have accurate statistics or a parameter setting changed?
>
> From: "Potluri, Venu (CT Appl Suppt)" <venu_potluri_at_ml.com>
> Date: 2003/12/29 Mon AM 11:44:24 EST
> To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
> Subject: A performance problem
>
> I have a performance issue in our 11.5.5 Oracle Apps production environment (Oracle 8.1.7.4). A concurrent job that feeds into another production envrironment (Oracle 9.2) and runs less than an hour
> typically suddenly took almost 20 hours to finish. The users are as expected up in arms calling my head on a platter. I looked at the statspack report for the database this job ran on.
>
> The Top5 Wait events were:
>
> Top 5 Wait Events
> ~~~~~~~~~~~~~~~~~
>
> Wait Event Waits Time (cs) % Total Wt Time
> -----------------------------------------------------------------------------------------------------------
> db file sequential read 15,978,336 5,809,277 57.28
> SQL*Net message from dblink 3,868 1,960,168 19.33
> db file scattered read 2,460,279 943,252 9.30
> control file sequential read 907,148 300,572 2.96
> pipe put 2,033 208,850 2.06
> -------------------------------------------------------------
> -> cs - centisecond - 100th of a second
> -> ms - millisecond - 1000th of a second
> -> ordered by wait time desc, waits desc (idle events last)
>
> Avg
> Total Wait wait Waits
> Event Waits Timeouts Time (cs) (ms) /txn
> ---------------------------- ------------ ---------- ----------- ------ ---------------------------------
> db file sequential read 15,978,336 0 5,809,277 4 970.3
> SQL*Net message from dblink 3,868 0 1,960,168 5068 0.2
> db file scattered read 2,460,279 0 943,252 4 149.4
> control file sequential read 907,148 0 300,572 3 55.1
> pipe put 2,033 2,032 208,850 1027 0.1
>
>
>
> Breakdown of Wait time
>
> Event Time Percentage Avg. Wait Per Execute Per User Call Per Transaction
> db file sequential read 5809277 60.16% 0.36 0.68 8.22 8762.11
> SQL*Net message from dblink 1960168 20.30% 506.77 0.23 2.77 2956.51
> db file scattered read 943252 9.77% 0.38 0.11 1.34 1422.70
> control file sequential read 300572 3.11% 0.33 0.04 0.43 453.35
> pipe put 208850 2.16% 102.73 0.02 0.30 315.01
>
> Here are the top SQL statements ordered by physical reads per execute: (these two happen to belong to this long running job)
> Statement Executes Physical Reads Reads/Execute Hashs Value % of Total
> INSERT INTO ML_MGMT_MCS_FEED SELECT /*+ ORDERED INDEX(MGNAL ML_MGMT_DIST_NAT_AC_LKUP_X1) USE_MERGE(BAL) */SUBSTR(GLCC.SEGMENT3,1,6) CENTER,SUBSTR(MGNAL.GL11PROD_ACCOUNT,1,5)
> ACCT,SUBSTR(GLCC.SEGMENT2,1,10) NEW10,SUBSTR(GLCC.SEGMENT6,1,6) PRODUCT,SUBSTR(GLCC.SEGMENT5,1,4) TRANSTYPE,NVL(SUBSTR(MGNAL.GL11PROD_ACCOUNT,1,5
> 13 9737644 749049.54 1419451399 30.18
> SELECT DISTINCT ENTITY,ACCOUNT,COST_CENTER,INTERCOMPANY,TRANSACTION_TYPE,PRODUCT,LOCATION,CHANNEL,FUTURE,PERIOD_NAME,SUM(BAL) BALAMOUNT,SUM(MTD) MTDAMOUNT FROM (SELECT DISTINCT
> ENTITY,ACCOUNT,COST_CENTER,INTERCOMPANY,TRANSACTION_TYPE,PRODUCT,LOCATION,CHANNEL,FUTURE,PERIOD_NAME,0 BAL,(ABS(NVL(MTD_TRANSACTION_DR_AMOUNT
> 30 5839191 194639.70 2733501134 48.27
>
> I am not sure on how to interpret the SQL*Net message from dblink wait event. Obviously we have a db link on this database pointing to another production database into which the data is being fed.
> Does this wait event indicate a network issue more so than a database issue? What else jumps out here? Thanks.
>
>
>
> Venu Potluri
> Oracle Financials DBA
>
>
>
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.net
> --
> Author: Potluri, Venu (CT Appl Suppt)
> INET: venu_potluri_at_ml.com
>
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-- 
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Author: <ryan_oracle_at_cox.net
  INET: ryan_oracle_at_cox.net

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Received on Mon Dec 29 2003 - 11:09:25 CST

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