Core Data Setup

[tripp13]

I have three questions for any one that would be kind enough to give their opinions and advice.

1 - When taking values from an attribute in an entity IOT sum them, which is the better, preferred method...using a predicate, placing them in a dictionary, or storing them in an array?

2 - When using a splitView app, is it best to display every pushView in the rootView, or separate the pushes between the rootView and detailView. For example, in the rootV, you push the add button and a pushView is displayed in the rootV where you enter the data, tap save, it pushes back to the parentView in the rootV where all your "names" are displayed. THEN when you click a cell, it pushes a view onto the detailView where you can tap another add button to add additional details about that name, click save, and back in the detailView that displays all the individual details you have entered over time in a tableView. When you hit the back button, you're back to the parentView of the detailView. Doing the second method allows me to show more data in the detailView tableView, but takes away my ability to show other data in the parentView of the detailView. Doing the first prohibits me from selecting a new name in the rootView until I pop back to that parentView. Any thoughts?

3- I'm considering adding a tabBar. If the additional tabs are not related to eachother and I want to use core data, do I add a new core data model for each tab, or create new entities in what I already have and only create relationships to those entities for that particular tab?

And a last question I just thought about. I'm not using any xibs for my viewControllers except for the the detail and root that are created when you build a new project with a splitview. How do I add a toolbar to the keyboard and how do I get the view to scroll up when I click in a textField that is a subview of a cell? The standard way does not work and since a scrollview is included in a tableView, I don't need to add one. This one has been frustrating me for a while and isn't too necessary based on my current layout, but it would be nice to know for future reference.

Thanks, y'all. Looking forward to your responses.