New data package: what is expected from server?

I'm studying the ticket app.

It dizzies at first but after a while you can easily follow and learn from it.

But, IMHO, is an unrealistic scenario:

Business applications normally deals with hundreds and thousands of records not only few tens.

Nevertheless I have no clue on how server should send data to the application.

Lets look at the fields of ticket model:

Code:

    fields: [
        'status',
        { name: 'projectId', reference: 'Project' },
        { name: 'creatorId', reference: 'User' },
        { name: 'assigneeId', reference: 'User' },
        { name: 'created', type: 'date' },
        { name: 'modified', type: 'date' },
        { name: 'modifiedById', reference: 'User' }, {
            name: 'statusName',
            depends: 'status',
            convert: function(val, rec) {
                return this.owner.getStatusName(rec.get('status'));
            }
        }
    ],

Most of them are FKs.

Do I have to send from server only the columns specified by the model or do I have to include (nested) each referenced entity? (No idea how the JSON would be in the latter case...)

If former, do I have to load ALL the referenced entities to memory?

I mean, all Projects and Users?

What if we have 1000 Users?

On the other hand:

I just crafted an application which uses a products catalog which has +/-40,000 items. If I have some reference to such entity (Product) from other models (say OrderDetail) do I have to keep the 40,000 items in memory?

Seems that the "magic" of the new data packages just wont work on large datasets

Regards.