You have a MySQL replication setup and you intentionally stop the SQL thread on the slave.

What are two reasons that you may stop the SQL thread on the slave while keeping the I/O thread running?
(Choose two.)

Consider:

Which statement best describes the meaning of the value for the key_len column?

You are using the mysqldumpslow utility to view the contents of the slow query log.
You notice the letter N and the character string `S' in a number of locations in the output.
What does the N indicate?

Consider the join_buffer_sizeparameter in MySQL Server.
Which two statements are true about the join buffer?

One of your colleagues is trying to make a change using the mysql command-line client for his or her application session.
The colleague instant messages you this command:
mysql> SET SESSION max_connections = 200;
Why does the command fail?