I have small confusion between Applymap() and joins?
I think in applymap() a small drawback is there
what applymap() do, we can do by the joins and drop the table.
my idea is We can use the join to bring one filed to another table and drop the table.
in applymap() every time it looks into the table and it takes more time than a join so join is good?
is it correct?
i wan difference between applymap and join;
thanks in advance
It is always good practice using joins all data is reside in on single data source in developer's point of view where us when if there is specific requirement occurs in this scenario you should use apply map also
go through this discussion
hope this help you.
Applymap is for the Reference lookup type of requirement.
The Mapping load only takes two fields in the table.
However Join can be used if you want to select a result set of the source tables.
Joins can work on more than one Field and their values with four types(outer, inner,left and right).
It all comes down to how much data you want to combine. A JOIN is very flexible / powerful but also a resource hog. Mapping tables are extremely fast but you won't experience any improvement on small data sets.
Most long-time QlikView developers tend to prefer applymap to any JOIN simply because of its efficiency. When a document has to be reloaded in a densely populated QDS environment, every second and every MB saved is crucial for achieving optimal performance.
There is no absolute thruth that tells you when to use this, and when to use that technique. You should always try what you think is best. That's a good way to develop your "Fingerspitzengefühl" (aka QlikView Experience)
first of all its upto requirment. whenever possible its better to go for Applymap
bcoz, when u compare the performance of Applymap and join (big data). Applymap perform better