I have to run one time 10 mysql queries for one person in one page. Is it very bad? I have quite good hosting, but still, can it break or something? Thank you very much.
Well there are big queries and small trivial queries. Which ones are yours? Generally, you should try to fetch the data in as few queries as possible. The heavier the load is on the database server the harder it will be to serve the clients as the traffic increases.