Question

i want to know what is the right way to do it .

We have area which can be northamerica, southamerica

we have goelocations which can be slc, murry, peru, mexico

so, one area can have many geolocations.

table for this is

ID      Area    Geolocation  
1       NA      slc  
2       NA      murry  
3       SA      peru  
4       SA      mexico  

If number of area and geolocation are very limited and not expected to grow do you see a problem in this type of design vs table with FK like below

Area table

ID      Area  
1       NA  
2       SA  

Geolocation table

ID    Geolocation     AreaID  
1       slc            1  
2       mexico         2  
3       peru           2  

which one will be easy to query and use in a php application?

Answer 1

Even though denormalization doesn’t cost a lot because, as you say, the geolocation set is small and stable, it’s still worth having a normalized table (as with your second option). You may decide to add (say) centralamerica or other regions. Or you may need to change the encoding used. The whole point of normalization is to make it easier to deal with changes you did not expect, not just the ones you can foresee.

The performance penalty for lookups is very small (if there is any at all). Updates will be easier and the data base will probably be smaller with an FK-based schema.