Analysisng statspack for hard hitting queries

[hrishy]

Hi

I have a statspack report (attached here)
and i am confused on which queries should i be looking into that would give me the maximum performance benefit.

I feel we should be looking into the insert statement

regards
Hrishy

[davey23uk]

the ones that cause the users the most pain

[hrishy]

Hi Davey

Thank you for taking your time out and having a look at this.

I am working remotely and the development team has asked me to look into this as they want a expert opinion from the DB side .

regards
Hrishy

[davey23uk]

the only thing that matters is what the users thing, if you tune a statement to run in half the time but the users are still annoyed by something else you havent solved anything, but lookk at your hard parses, 112 per second!

[hrishy]

Hi Davey

Once again thanks for your valuable advice

I have noted down a few things but when it comes to statspack more experienced eyes the better

Instance Level

1)Hard Parses are high
2)Rollback per transaction is high
3)Execute to Parse is low

Wait Events
enq: HW - contention
enq: TX - row lock contention
enq: TX - index contention
db file sequential read

are all appearing.
I guess the contention on enques is due to the fact that session are holding locks which other sessions wants and are not commiting.

TX - index contention occurs when many sessions try to insert but they need to wait due to non availibilty of ITL can be alleviated to some extent by increasing PCTFREE on the table

log file parallel write need to check if all the logfiles are on the same disks and the sma econtroller

Logbuffer size is only 14Mb which is small

SELECT  /*YANTRA*/   LT_RECIPE_ALIAS.* FROM LT_RECIPE_ALIAS LT_
RECIPE_ALIAS     WHERE LT_RECIPE_ALIAS.RECIPE_KEY=  :1
 
SELECT  /*YANTRA*/   LT_RECIPE.* FROM LT_RECIPE LT_RECIPE     W
HERE LT_RECIPE.IMAGE_KEY=  :1

SELECT  /*YANTRA*/   LT_IMAGE_ALIAS.* FROM LT_IMAGE_ALIAS LT_IM
AGE_ALIAS     WHERE LT_IMAGE_ALIAS.IMAGE_KEY=  :1

INSERT   /*YANTRA*/   INTO YFS_AUDIT(AUDIT_KEY,AUDIT_TRAN_KEY,AU
DIT_CONTEXT_ID,REFERENCE_1,REFERENCE_2,REFERENCE_3,REFERENCE_4,R
EFERENCE_5,REFERENCE_6,TABLE_NAME,TABLE_KEY,AUDIT_XML,OPERATION,
LOCKID,CREATETS,MODIFYTS,CREATEUSERID,MODIFYUSERID,CREATEPROGID,
MODIFYPROGID) values (:1,:2,:3,:4,:5,:6,:7,:8,:9,:10,:11,:12,:13

Is there anything else ?
are my observations right ?