I just opened https://issues.apache.org/jira/browse/ARROW-2152 to start the
discussion about adding a UUID type to the Arrow format specification. In its
essence a UUID is simply a 128bit array but there are often special classes
used for it, e.g. java.util.UUID in Java and uuid.UUID in Python. These provide
special functions for them as well as sometimes the knowledge that a column is
a UUID could be beneficial during computations. Other data systems like
Postgres or Parquet also have a special UUID type.
While there is only a small difference to a 128bit fixed sized binary array, I
think providing the respective object model accessor is already a good benefit.