Group data before or after importing into the model?

[rpeer]

Hello

I have a long table with transactions. There are several transaction a day. In the reporting I'll only need the daily sum of successful transactions.

Now I'm wondering whether I should

a) create an additionaly table in the query editor based on the full transaction table and group/sum the data per day

b) do this in the model with measures (I guess it's possible somehow to do this -> I'm not yet very familiar with measures and such)

Wouldn't it be better to do this in the query editor because the dashboards working based on the model work faster (no grouping). The import will only be once a day. 

[jstorm · Accepted solution]

It would be best to load all the data and manipulate it with measures so you can develop more insights.  PBI can handle millions of rows efficiently so it shouldn't be a problem.