Hive's binary data types seem very similar to strings with some exceptions:
- no implicit/explicit cast to any type except string
- bit different built-in functions than for string, but some functions accept both string and binary (e.g. concat)
- written to text files with base64 encoding
(see https://cwiki.apache.org/confluence/display/Hive/LanguageManual+UDF )
I didn't look around about client support yet.