2 or 3 text chars VS number as key for indexing and relation... what best?
I am afraid that could be a very fulish question, the fact is that I have some large files that I imported to a filemaker project, those files are now tables with adresses, post codes, districts etc... this are oficial from our post offices in Portugal CTT (they can be downloaded from the oficial site).
The thing is that they advise to keep some fields in Text, fields that are used as key fields, example: 01, 03, 12 etc... also the 3 digit post code like 001, 003, 010 etc ...that I use in relations.
Is that more eficient? or will be better to change the field types to number. I have relations, indexings etc on those fields.
On my last years on SQL databases I never had done key fields with text chars, I dont know if I never had to, or if it was best pratices... simply dont remember why.