Why a table can't be picked as it is, read from its definition (PLAN ยง6.2.6)

Enumeration Members

LENGTH_UNKNOWN: "lengthUnknown"

a CHAR(n) column: typed with a length of 1

TYPE_UNKNOWN: "typeUnknown"

an OTHER or ARRAY column: typed as a bare String

UNAVAILABLE: "unavailable"

a binary column: the engine can't type the table