I would like to build a database for visitors at my site to add their info. The fields I’m thinking to add are:
First name
Last name
Email address
Telephone number
Last loc.
Current loc.
Occupation
Notes

I don’t want the users to register to add their entry to the database and the save goes when searching.
When the users add a record I want the entry to search against the database if the name or email address already exist. If the either exists I want a form to display the record and ask the users if this is he/she. If it is the user I want the user to update their record if not then they can register. I also want all new and update entry to be validate before available for viewing.

I not sure if I covered all the basis for this db regarding its design. So any input or reference information with be helpful.

With the following fields above, I’m looking for a rough estimate of the number of records require before seeing a slowness with the DB?.

Thanks
Huckle