I understand how CL works for single partition read operation but I'd like to understand how is requested consistency level implemented for a table scan query or token range query.
Example: SELECT * FROM table WHERE token(key) >= start AND token(key) <= end. Does Scylla ask requested number of replicas to acknowledge read for each partition? Or is this somehow achieved once for the whole token range?
It's done once per page. A page is a megabyte's worth of rows, and can contain multiple partitions or part of a single partition.