manipulating 15+ million records in mysql with php?

Question

I got a user table containing 15+ million records and while doing the registration function i wish to check whether the username already exist. I did indexing for username column and when i run the query "select count(uid) from users where username='webdev'" ,. hmmm, its keep on loading blank screen finally hanged up. I'm doing this in my localhost with php 5 & mysql 5. So suggest me some technique to handle this situation.

Is that mongodb is good alternative for handling this process in our local machine?

Thanks, Nithish.

Answer 1

If you just want to check that it exists or not, try not using the count. Just a simple select username from users where username='webdev' LIMIT 1 may be faster.

ALSO, change the column type to varchar, if it's not already so. Don't user text type. It's much much slower.