topic Re: Avoiding Aggregation in QlikView

Avoiding Aggregation

Tue, 28 Jan 2014 20:05:29 GMT

hi,

can any body tell me how to avoid aggregate and increase the performance for regular faced scenarious.

regards

Mahesh T

Re: Avoiding Aggregation

Tue, 28 Jan 2014 20:13:22 GMT

Hey Mahesh,

Can you post a sample file explaining where you wanna avoid using aggregation. Aggregation is one of the most useful tools and some calculations simply can't be done without aggregating.

Thanks

Re: Avoiding Aggregation

hic — Tue, 28 Jan 2014 20:24:06 GMT

All calculations are aggregations. See http://community.qlik.com/blogs/qlikviewdesignblog/2013/08/06/it-s-all-aggregations

HIC

Re: Avoiding Aggregation

Tue, 28 Jan 2014 20:31:30 GMT

Hi Henric,

i want to avoid aggregate function for increasing performance during like un nessary use of aggregate function used in optimization like that

regards

Mahesh

Re: Avoiding Aggregation

Tue, 28 Jan 2014 21:14:04 GMT

An Eternal "It Depends" - Removing the aggregations may or may not increase performance.

Can try things such as:

Using Set based functions where possible (Depends on what you are doing, sometimes Set performance is better)
Pre-aggregation in the load, possibly through construction of "Summary" or other helper tables (e.g. rather than working off a Fact type table, construct a "summarized by Month(day/week/customer/minute/whatever" type table)
Moving things into individual charts, and minimizing the number displayed at one time (QV is smart enough to not calculate what you can't see)

Re: Avoiding Aggregation

hic — Tue, 28 Jan 2014 21:44:28 GMT

Again - all calculations are aggregations. It doesn't matter if you write an aggregation function or not, QlikView still needs to aggregate. Read the blog post.

If you want to increase performance, there are several things you can do, but avoiding using an aggregation function does not help. The three bullets in Jim Schepflin's answer are all things that potentially can improve performance.

HIC