Recomended Database?

Hello dear,
First of all I want to thank you for this magnificent work, I planning on setting up a GPS server that would host 100~500 cars, What Database you would recommend for this size of service?

Thanks again.

I would recommend MySQL or PostgreSQL.

Thank you Anton for this fast reply, is the free version of MySQL is enough for this size of traffic and for the future too?
I mean is there a known limit for the free version database that when I reach it then a paid version database is required for the job?

Is there a non-free version of MySQL?

yea there is :) MySQL Enterprise Edition

It's the same server with some extra enterprise features on top. There are no limits in the free version.

MySQL it is then,
Thanks alot and sorry for the inconvenience.
Great work.