To Store or not to store the data in a facebook application

I am creating a facebook applicatioon using PHP-SDK and GRAPH-API. I feel like saving the email address of the users who play my app. but i have limited resource, i am still a student with financial crunch. Please let me know what im开发者_Go百科pact the following feature will have on my app.

1. a mysql database with three columns serial number, id, email address.
2. if the user comes to play the app, get his details.
3. perform an exhaustive search in the id column, if not found update it.

Performing these steps, will take how much execution time and stuff, please let me know, what long term impats it can have on my app.

Thanks a lot.

An Innodb storage and making the id field unique and you'll have no issues whatsoever ;-)

With proper indexing, I don't see why this would be a problem. If you're paying for the resources to host your script, then storing this small amount of additional data should have a negligible impact on your resource usage.