topic Re: Which option is the best considering optimization and performance tuning when you have two fact tables in Qlik Model? in App Development

Which option is the best considering optimization and performance tuning when you have two fact tables in Qlik Model?

rupalimane1390 — Mon, 21 Jun 2021 11:24:08 GMT

Which of the following option is the best considering optimization and performance tuning when you have two fact tables (having many common columns) in Qlik Model?

1. Linking two fact tables

2. Concatenating two fact tables

or is there any other way to handle ?

Thank you in advance.

Re: Which option is the best considering optimization and performance tuning when you have two fact tables in Qlik Model?

Pertjo — Mon, 21 Jun 2021 19:42:59 GMT

If you have more than one common column between two tables you will get a synthetic key.
In that way, it is a lot better to concatenate them. But linking two tables and concatenate is two different things.
If you concatenate you won't have any connection between the values in the different tables. You will just get additional rows.

If you want to link you could either create a good key and join (left, right, inner and outer) or if you want specific fields you can use the apply map option,

Re: Which option is the best considering optimization and performance tuning when you have two fact tables in Qlik Model?

rupalimane1390 — Tue, 22 Jun 2021 07:01:45 GMT

Thank you @Pertjo 🙂

Yes, seems concatenating is the best option as two fact tables are absolutely different from each other but share many no. of common columns. I do have 2-3 dimensions which need to be linked with both the fact tables, in this case I can make use of joins and a composite key to map them.