Description
As we support BOOLEAN as a first-class citizen data type, we should have a way to serialize/deserialize a NULL value. This will prevent us from having to coerce it back and forth to a DECIMAL when indexed and allow it to be used as a nullable column anywhere in the primary key constraint. We'd need to add a PDataType.isNullable() instead of relying on PDataType.isFixedWidth() to infer whether a nullable column is allowed in the middle of a primary key constraint.