an be read as the column type.

 <pre>
 |        | boolean byte short char int long float double String byte[]
 |----------------------------------------------------------------------
 |boolean |    X                                            X
 |byte    |          X     X         X   X                  X
 |short   |                X         X   X                  X
 |char    |                     X                           X
 |int     |                          X   X                  X
 |long    |       