performance issue!

[#1]

hi,

my client is having many unrequired data fields because of which it is taking a long time to reload. keeping this problem in mind i have commented those unrequired fields but still the performance of that qlikview application hasn't improved.

what should i do next? does wrong data modelling also affects the performance? if you answer 'yes then i shall be removing some tables...? kindly help!

[#2]

Keep in mind that commenting out fields from the LOAD statement does not make any difference to what is actually transferred from the database server - it only reduces the size of the data model in QV.

(I am assuming that you load from database tables, not from files.)

It is unfortunately fairly common to use SELECT * in the Select-statement in QV. This is contrary to best practice in database development, and has been since relational databases became common.Best practice is to list exactly the columns that you want - even if that includes all columns currently in the source table.

Also, I sometimes see scripts where the WHERE condition is in the LOAD statement, not in the SELECT statement. This means that the complete table has to be loaded to the QV server, and then only some of the rows will be loaded into QV.

So, if your performance issues are related to the amount of data transferred across the network: Try to replace SELECT * with SELECT <column-name-list>, and move any WHERE conditions from LOAD-statement to SELECT-statement.

Best regards, Vegard.

[#3]

hi vegard,

thanks for the help. actually what is happening that one of the sheet in qvw is taking a long time to open. as said earlier i was commenting the fields but it didn't made any noticeable difference. what should be the next easy step to that i should do. because the client for which i m working for wants the application to be done within 2 days of time. further on changing the data modeling will make the task longer as it will require more time and resources.

regards

gaurav

consultant-bi

[#4]

Dear Gaurav,

Please specify you are fetching data from which data source. its oracle , Sap or some other.???

and you are selecting all the tables fileds or some restrictions are made..

Regards

Ashwin

[Anonymous]

Obviously the problem is not about slow data load, but about run-time performance. The issues could be related to :
1. Too much data
2. Ineffective data model.
3. Too complex chart calculations
4. Macro is running too long.
Or it could be combination of several factors. Each require different solutions, so the first step will be to find out what's going on.