Normal Description
Please improve the ALTER TABLE statement so that it automatically checks the data in the table against the new data type to change to. I know that it's in the docs that this is the current state and not checked. It may be the easiest and fastest way for implementation for now but it should be improved in the future.
docs on ALTER:
The column must already have a type in the column family metadata. The column may or may not already exist in current rows (no validation of existing data occurs). The bytes stored in values for that column remain unchanged, and if existing data is not deserializable according to the new type, your CQL driver or interface might report errors.