Is there an alternative to DataSet in c# for calculated fields?

Question

WPF

Good day!
I have a DataSet, which stores the structure of tables and relationships between these tables (about 30 tables). In my WPF application, at startup, I load data from xml into this DataSet, when I exit the program, accordingly, I save the data to the same xml.
In the DataSet, in some tables, mathematical expressions (expression) are used in the fields, it would seem that it’s okay, but when there are a lot of records, when loading data from xml, the program freezes for 10 minutes. I found out the reason, this is due to calculated fields, in particular because for fields that use aggregate functions of the Sum() type.
What can you advise to use as an alternative to DataSet'u to calculate the values ​​in the fields?
To work with xml, nothing else comes to mind.

Answer 1

use classes instead of DataSet, and calculate anything inside the classes