I've faced with the following problem during development of middle+ size application:
When user select the specific value(s) in the list, for example, set of months ( a Qlikviewfield in Master calendar) - there is a delay in 15-20 seconds BEFORE QLIKVIEW STARTS TO RECALCULATE OBJECTS (object recalculation does not consume so much time = 2-3 sec). During this delay, all 16 cores of CPU are loaded up to 100%.
Details: QlikView 12.1 SR4, QVW size – 4Gb, 180M records х 80 fields in fact table, Star Schema (+10 Dic tables)
I’ve done and checked a lot in order to optimize performance:
No synthetic keys
Many flags (1/0) are pre-calculated in script and joined to fact table (it is the reason of 4Gb qvw size – there is no lack of RAM, the bottleneck is CPU)
All link fields between tables are numeric (autonumber)
No “if” and “aggr” functions in expressions
No “global” (started with = sign) calculations for variables. Anywhere they are used via dollar-sign expansion
Document Analyzer recommend just remove some unused fields - done
There are many (60) variables with expressions text
Some variables are used in Set Analysis conditions via $()
There are 3 data islands , BUT with Alternative State usage
I realize, the App is not simple and requires much CPU resources for processing, but the most of all I consider of DELAY between SELECTION and the start of object recalculation (EVEN IF THERE IS NOTHING TO RECALCULATE – ONLY LISTS ON SHEET).
Of course I think that hardware tuning could help – physical vs. virtual, Intel vs. AMD, disable NUMA. But not significantly …
Does anybody know what could cause the described delay in the associative model performance?