> Is it recommended to keep primary keys limited to a single field?
>
> I have an account_id in all tables, and I wanted to make the rec_id in all
> tables unique within an account_id, so the primary key would be based on
> account_id + rec_id. I like the idea of each Account starting at 1 for
> their rec_ids, though I know this is not necessary. I also want to do this
> in case I need to break out all recs in all tables for a particular account
> or customer. Initially, all customers will be hosted in one database for a
> web app. But there will opportunity for that customer to later host their
> own data, at which point, it be real easy to break out their data.
>
> The downside is that all my queries need to include account_id. Will this
> impact performance on SQL much greater than having a single field primary
> key ? Is there a recommended design for this ?
>
> It will work either way, I know. I'm just trying to get opinions on the
> preferred method out there.
>
>
> Thanks...
> Bill