I am working on a social networking site with a family tree that is GEDCOM-compliant. We need to decide if we should use a horizontal or vertical database structure for User profiles. So, I would like to know if anybody can answer when to use a horizontal database structure and when to use vertical database structure.
I found some answers for shopping sites where fields are not decided: a vertical database structure should be used. But I am confused about what to use for a family tree site. Should I use vertical or horizontal?
I assume you use a relational database like Mysql, Ms sql, Sqlite, Postgresql or Oracle for storage?
Gedcom is a standard for information exchange so you know how many columns you will have. Maybe the standard is extended with new properties in the future but it probably wont be a lot of new properties. You can easily extend a table with a few new columns.
I would use a 'horizontal' table and not a entity-attribyte-value-system (vertical table). Vertical table systems tend to be slow. They can't be properly indexed and confuse the query optimizer.
It becomes a different story when your users can define new properties in their profiles like eye colo(u)r or favourite colo(u)r themselves. How flexible do you want those profiles to be?