How many columns/fields can I have in a SOW topic? In a view?

AMPS doesn't have any practical limit on the number of fields you can have in a SOW topic or project into a view. Some of our customers regularly process multi-megabyte messages in production.

Bear in mind, though, that larger messages require more network bandwidth and, with a larger number of fields, each field requires processing. Although AMPS handles large messages well, the general messaging approach of providing only necessary data in a message is still a best practice.