how to avoid 'Allocated Memory Exceeded' issue?

[#1]

Hi All

     I have a chart:

2 Dimensions:  both are Cyclic group: Grp_Geo (geography group, as the first dimension) and Grp_Prd (product group, as the second).

1 Expression: Market share: sum(Sales) / sum(total <Grp_Geo> Sales).

And in the tab 'Dimension Limits', I show only the biggest vTop+1 products: (as i show 'others')

And i have a slider to adjust the value of vTop:

This chart mostly works pretty well as below shows:

but sometimes i changed the value of vTop, this chart said 'Allocated Memory Exceeded':

This happened mostly when i set the Grp_Geo to a more detailed level. The fact table contains 622M rows and 50 fields.

I want to know why this happened and how to avoid this?

Thanks in advance.

[danieloberbilli]

Please have a look at this thread and word-doc: Show Top Performers

http://community.qlik.com/docs/DOC-5187       

The Dimension Limit is very performance heavy - try to limit the results within the expressions like with the recommended rank() functions

[#3]

Thank you very much, Daniel. In this case do you know what is the right expression using rank() that if i want to achieve the same chart as i have posted? Thank you.

[amit_saini · Accepted solution]

Duo,

Normally, this happens when you are trying to show too many values on your table or when computing the table takes too much memory, depending on the RAM that is available on your computer / server.

This is not intuitively linked to the changes you are making to the table. If you keep it this way, the risk is that the message will appear "randomly" when the load is too high, looking like it's a bug.

Reloading, re-opening the app and stuff like this will just be a temporary fix but will not solve the root of the problem.

You have to try to reduce the amount of data you want to include in the table (think about the user experience) or use a machine with more RAM if you cannot shrink it further.

Thanks,

AS

[amit_saini]

Duo ,

For Rank function please see the attachments.

Thanks,

AS

[#6]

Thank you very much for your examples and explaination. I have fully understood the reason why the memory exceeded. I have thought about soluton to resolve this. Thank you very much again.

[amit_saini]

Cheers