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Hello Community,
Which one is better for performance wise, Link Table or concatenation?
- Regards,
Vishal Waghple
Hi Vishal,
Concatenation is performance wise good
REF : QlikView 11 for Developers....
Dear Vishal,
Finding a balance
We have outlined two ways for dealing with multiple fact tables in a data model. If we were
to ask which of these methods is better, we would need to say, again, "it depends." There
is no definite best, and the decision about which to use will depend entirely on the specific
scenario where it has to be implemented.
When deciding on data model design, you should always ask yourself if the "structural
asymmetry" we talked about before is something you could accept in your data model, or if
the asymmetry is highly significant and therefore you would prefer to live with the "additional
hop" in the data model.
Choosing between approaches can also impact the application's size. Take a look at both
of the files created using each of the preceding methods and see which one is smaller in
disk size .Can you guess why the link table approach produces a smaller file? It's because
we've taken out some fields from the relatively large fact tables and placed them into a
smaller link table.
For QlikView, both of these approaches are OK. They work as they should and there
should not be calculation differences resulting from using them one over the other.
As Kumar, i would say CONCATENATION
From Doc: QlikView Best Practices – Development.pdf
With SECTION ACCESS: Utilizing a ‘Star Schema’ design for the data model with NO LINK Tables. Link tables hurt performance greatly!
Fabrice
if you could choose, USE CONCATENATE
good luck!
Hello Kumar,
Why concatination is better than link table?
Can we use concatination every time rather than link table?
- Thanks and Regards,
Vishal Waghole
hi
Q.Why concatenation is better than link table?
Ans. Concatenation append the data in one table like join.
so performance of Concatenation is good.
Q.- Can we use concatenation every time rather than link table?
Ans.- No, it depends upon the data in your table.
through concatenation you merge one table in other table, for this at least one field must be common in both table.
note- link table only display the linking between two table when field are common.
but concatenation join the two table.
Concatenation is the best to use.