Qvw file size behavior before and after dimension modification

saveriospa — Wed, 18 Feb 2015 10:13:32 GMT

Hi to all,

i'm been studying "Qlikview Developer 11" and i noticed a curious thing in an exercise.

There is a fact table and different dimensions. In several dimensions there are non-matching values with the fact table, then is suggested how delete this non-matching values from the dimensions to reduce the size of the qvw.

To simplify i have loaded only one dimension (in addition of the fact table), before with non-matching values and after without.

From an original dimension of about 55MB, after i have a qvw file of about 33MB.

But, if i try to load only the fact table, the file size is about 54 MB.

The question is ... how it is possibile?

There is a compression of the data model only when i have loaded more than one table?

Summary

Size of file qvw loading one table at a time:

54273 KB Only fact table (57 fileds x 1256075 records)

255 KB Dimension with non-matching values (2 fielsds x 6209 records)

183 KB Dimension without non-matching values (2 fields x 2142 records)

54388 KB - Fact table and dimension with non-matching values :

Tables	#Records	#Fields	#Keys
Fact Table	1256075	57	1
Dimension	6209	2	1

34901 KB - Fact table and dimension without non-matching values :

Tables	#Records	#Fields	#Keys
Fact Table	1256075	57	1
Dimension	2124	2	1

The records number of the fact table is the same, because QlikView perform a full outer join, then there isn't a subset of record for the fact table driven by the dimension filtered (in case of a inner join).

For completeness, the fact table is loaded from a qvd, while the dimension from an access table.

Can someone help me understand this behavior?

Thank you all !!

Saverio

topic Qvw file size behavior before and after dimension modification in QlikView

Qvw file size behavior before and after dimension modification

Summary