Performance question

[#1]

Hello,

I have a company database with it's sales in fact table (date of sale, number of product, name of product, quantity, revenue, etc). There is above a picture of it's model.

Now, I need to insert a plan table, where I have the product key with it planned sales quantity and revenue. What's better:

1) I create another table and link it with the fact table.

2) Insert another column in the fact table and join this new information with the fact table. (All the other information in these rows with the planned information will have null value.)

3) Other option that I don't thought.

Tks

[#2]

Hi Eduardo

I think the best is to check what are youor keys in Plan table. Only Product, product-Date, product_date-vendor...

According to this you will find the best way to create the table at the right place.

best regards

chris

[#3]

I know where to link. What I want to know is if I'll have a best performance (considering processing time, space used, etc) creating a new table and linking it with the fact or put the information on the fact table (table "Fato"). What I'm worried about is that if I put the information on fact table, I'll have a lot of null values on table (useless allocated space) and if I create a new table, I'll not spend space, but probably I'll need more data processing.

[johanlindell]

Hi Eduardo,

I think null values will not take up space. I find the best solution often to be to concatenate the new data into the fact table. Best way forward is probably to make a quick test of both (or all three) scenarios and see which is best.

Whithout knowing the number of rows, distinct values etc it is difficult to advise.

Brgds, Johan

[#5]

Thanks.

Do you know a way to measure this tests in Qlikview?

[johanlindell]

Check the Task Manager, cpu-time and mem usage for a high-level check both when reloading the file and when opening and navigating in the application.

Check how big the document becomes and time to change tabs, minimize and maximize objects.

For a more detailed check look in the Objects-tab in "Sheet properties". Here you find "Calc time" and "Memory" for each object.

Brgds

Johan

[#7]

OK, thank for the tips. I'll try here!