If a field in a record read from a source contains a type that is not supported, such as a short, then Hydrator fails with a cast exception. Instead, it should promote the short to an int and read the record. Looks like we do the type promotion for schema already, since the schema uses int when the source field type is short.
We saw an issue where the JDBC driver for SQL Server would convert SMALLINT to short, and Hydrator would fail to read the record. It confuses users since the Hydrator schema for the same source says the field is int, but the error message says cannot cast short to int.