In CQL indexed column values can be used to prune the rows that are returned. I think there is value in allowing column values to prune the rows selected even when they are not indexed. The row key specification narrows the set of rows visited. The column value specification narrows that still further. I don't really understand why this isn't supported.
My actual problem is that I would like to scan a range of rows (by token not key) but only return those where a certain column is >= some constant. (For various reasons we cannot use Hadoop). Is there any chance of this sort of thing being added to Cassandra?