Thanks for the help, and for different design options it really helped me. I had a look on vertical design and horizontal design and this is some cons and pros in general for vertical design
Advantages: • Avoid null values and utilize storage • Avoid constant schema changes due to adding columns • Avoid performance issues which may encountered when a the table is very wide for specific queries Disadvantages • Queries written against the vertical design became cumbersome. • Multiple joins to pull back each attribute. • Data needs to be converted to the horizontal design in many cases so you need the contribution modules such as table funcs • Data domains are problematic and hacks here can be used such as fix your attributes, or using many tables.... ------------------------ the car speed is 240 the car has an airbag Here the first value is integer and the second value is boolean. Consider that I have this table structure feature (feature id feature name) car (car id, .... ) car_feature (car id, feature id, value). the value attribute might have different domains. How can I model this using postgres and using ANSI compliant design ? Regards
