[jnewhouse]

It natively supports a limited set of Columns. Basically boxed primitives, java.util.Date, joda.time.DateTime, and arrays and double arrays of both boxed and unboxed versions of the preceding. The list of Columns being used is used to read and write to a byte buffer. The byte buffer is almost entirely the field's data, with one or two bytes describing how the subsequent field is encoded. Nested objects aren't handled out of the box, but there is the capability to define a UserRowField that allows for serialization/deserialization to bytes of any Serializable class. This gets used for our SQL map-reduce function a lot. The downside is that you need to have the UserRowField implementation in your classpath in order to read the Row, which is not generally the case.