QlikView performance

[#1]

hi,

my doubt is about performance the QlikView

what is the best way to get a sub-total during script load?
using "resident" or read the QVD file?

thank you

[#2]

Resident It will give you a better preformance because the table is already in memory.

[#3 · Accepted solution]

Hi Fabio,

reading from a qvd-file you can be done in two ways: optimized and "normal". In optimized mode it is similar to copying blockwise data (fast as lighning). But if you use a function like sum(), date() or what ever, QV has to read every row for evaluating and calculating. This is mostly faster then reading from excel or a database table, but as mentioned above, the optimize mode is the very fastest. So you have deside what kind of formatting etc. you can afford during creating your qvd to be able to use afterwards optimized mode from qvd to qvw. Another possibility is to load your data (independent from optimized qvd) and afterwards read from the resident table which is then in RAM. Your strategy depends on what functionality you want to achieve and from the data volume, because resident loading is also very fast, but you need the according memory at one time.

Regards, Roland

[#4]

To summarize:

If you have enough memory: Use resident ( faster)

Else, read on the file and aggregate at the same time.

Rgds,

Sébastien

[#5]

Thank you everybody for all answers!