Multithreading in MySQL?

Question

Are MySQL operations multithreaded?

Specifically, on running a select, does the select (or join) algorithm spawn multiple threads to run together? Would being multi-threaded prevent being able to support a lot of concurrent users?

Answer 1

Several background threads run in a MySQL server. Also, each database connection is served by a single thread. Parallel queries (selects using multiple threads) are not implemented in MySQL.

MySQL as is can support "a lot of concurrent useres". For example Facebook started successfully with MySQL.