Re: Data modelling questions.

Hi, Robert, usually for 1:1 relationship, you will put them into one entity. However, with wharehousing and other applications you may need to split them if you want to increase the performance. If it were not for special purposes, I'd feel it like 5nf. There is no relation between talent and talent photo. But each has an id associated with it. Another example is a group of people with two type of talents. Type 1 - langueages, such as English, Spanish, German, Japanese, etc Type 2 - football, tennis, baseball. You can put them into one table as:
(person id, talent type1, talent type 2). But what if some people has only talent type 1 or talent type 2. Some people have both. In that case you split into two entities: (person id, talent type 1) (person id, talent type 2).

The second group:
Talent (talent_id, talent_name)
TalentPhoto (talent_photo_id, talent_photo, talent_id)

I'd feel more like a 1:M relationship with 1 talent_id has many talent_photo_id senario. Otherwise there is no need to do this way. Received on Wed Oct 15 1997 - 00:00:00 CDT