Today marks my first blogging of “Best Of QlikCommunity” (BOQC) where I plan to highlight what I find to be particularly useful or interesting posts on the QlikCommunity Forums.
There are cases when the ApplyMap() function is a very useful alternative to Join. For some time I have noticed both Oleg Troyansky and Michael Nordstrom dropping this hint on QlikCommunity but I never quite understood the power of the technique until a post Oleg made today:
The original forum question was how to multiply two fields from different tables to derive a new calculated field. The tables share a common key field.
I usually would have approached this with two Joins. That approach works, but sometimes I don’t really want my data model to reflect Joined tables. I just want to do the calculation.
If you want to see the ApplyMap() solution, read the post linked to above. The thread explains it better than me repeating it here.
3 thoughts on “BOQC: ApplyMap instead of Join”
As I’ve wrote in the QlikView thread, you should consider lookup() for better use.
I updated the QlikCommunity thread with my experience with lookup. I agree that lookup() is handy, but I find it too slow when processing larger quantities of rows — 10K +.
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