+(defgeneric db-type-has-intersect? (db-type)
+ (:method (db-type)
+ (declare (ignore db-type))
+ t)
+ (:documentation "T [default] if database-type supports INTERSECT."))
+
+(defgeneric db-type-has-except? (db-type)
+ (:method (db-type)
+ (declare (ignore db-type))
+ t)
+ (:documentation "T [default] if database-type supports EXCEPT."))
+
+(defgeneric db-type-has-auto-increment? (db-type)
+ (:method (db-type)
+ (declare (ignore db-type)
+ nil))
+ (:documentation "NIL [default] if database-type supports auto-incrementing columns."))