Looping Through A Dataset - Object-oriented Approach

The problem is as follows, a group of users (~50k) must be filtered from a DB, four fields for each user must be saved into a variable, then a second process will take each user and proceed to enable some licences into another system/platform. Both processes will be developed into the same application.

My first attempt was basically a query looping through the users but I wonder if thinking in objects is a better approach.

I was thinking in a structure inside an object to hold the 4 parameters, then pass each user object to the other object however considering the amount of data I'm not sure if this is fine.