Data population slows down application performance

We need to load data from source table to summary tables on daily basis. But we don't want to slow down our application performance while data population as the data is fetched from summary table using stored procedure to show on the application.

How can we do it?

My suggestion is that we should run oir population process in separate database and once the data is loaded into summary tables we will move data from there to here. Also i have no idea if the databases on the same machine still slow down the performance or the databases should be on different machine.

Please suggest me better way than what i have suggested.

Thanks

which data is your app pointing to? source or summary?

Application is fetching data from summary tables.

It's summary

how much data are we talking about here, how many rows and how are you doing this transfer of data and how often?