Thursday, May 19, 2011

Query performance issue : Dedicated Client Vs Thin Client

Very strange behaviour I observed today while working on a performance issue where whenever user do a query in Purchase Order Pick applet, query was taking more than 1 minute to execute in thin client but the same query behaves perfectly fine in dedicated client.

So while working on any performance issue, you always want to see the performance on dedicated client as well, so I did the same.

1. Took the same SRF running in thin client, and connect it to the Dedicated client.
2. Followed the same steps: open the pick applet and queried the Purchase Order#

To my surprise, on dedicated client the PO# query took only 6 seconds which is quite acceptable performance. So, this is the issue I faced first time when the query is running slow in thin client but not in dedicated. Now, lets try to find out what exactly is going on behind the scene.

I referred the spool file and took out the culprit query. Execution time mentioned in the query was same around 6 seconds. I ran the
"Alter Sessions" commands as mentioned in my earlier post and ran the query. It again took only 6 seconds.

***** SQL Statement Execute Time: 6.014 seconds *****

hmmm..... now it looks like everything seems working fine from configuration perspective but why is there a difference in the query execution when run in Dedicated client Vs Thin client???

I was looking into the issue more and found that when I did a query in PO# field with value "1234" and it returned multiple records with PO# like: 1234, 12345, 1234a etc. So, it is quite clear that
"AutomaticTrailingWildCards" parameter in the CFG was not set to False. But, anyways the query should perform similar in both the dedicated and thin client, no matter this parameter is set to False or not. Though, this thought is quite logical but even then I wanted to give a try by disabling it. So, I thought of disabling it only on the "PO#" field on the pick applet, so that whenever user do a query on PO# field, system should not put the "like" keyword in the SQL generated at the backend.

I put the following User Property on the business component:

Name : Disable Automatic Trailing Wildcard Field List
Value : Purchase Order Number
I compiled the SRF, tested it in dedicated client, it worked fine. Now it is the time to test it in thin client as well. At this moment I was not sure how it would behave. I put the same SRF on thin client and performed the same steps for querying the Purchase Order#, I got the result in around 6 seconds. A big smile and relief too, but again I don't have the correct explanation yet for this problem why is it happening, but this user property came as the life saver :)

If you ever faced this kind of performance issue and know the exact reason please comment.


  1. i am facing the issue as :
    Requirement : When i am clicking on button it will take records from excel file and load.
    Issue : it is working fine in dedicated client but not working in thin client.

    please suggest me ASAP......

  2. Dedicated clients and think clients have a different way of connecting.

    This works for both: Set siebelApp = GetObject("", "Siebel.Desktop_Integration_Application.1")

    make sure you have the correct reference files checked in Tools--> Refrences in the VB Editor