How can I add sort criteria for search api views?

Question

I set up a view with search api data according to this, but the sort criteria available in each view are not complete. I'd like to sort on some fields (indexed) that are not showing in the list. I'm wondering if I need to use a hook to alter the query, or if there's a configuration option somewhere that I've not read about.

Answer 1

I just discovered that if I re-index the fields (in this case, first name and last name) as strings, rather than the default fulltext, they are made available to sort on in views. This is great news.