How can artificially create a slow query in mysql?

I'm giving a hands on presentation in a couple weeks. Part of this demo is for basic mysql trouble shooting including use of the slow query log. I've generated a database and installed our app but its a clean database and therefore difficult to generate enough problems.

I've tried the following to get queries in the slow query log:

Set slow query time to 1 second.

Deleted multiple indexes.

Stressed the system:

stress --cpu 100 --io 100 --vm 2 --vm-bytes 128M --timeout 1m

Scripted some basic webpage calls using wget.

None of this has generated slow queries. Is there another way of artificially stressing the database to generate problems? I don't have enough skills to write a complex Jmeter or other load generator. I'm hoping perhaps for something built into mysql or another linux trick beyond stress.

Checkout mysqlslap. You can pass one of your webapp's queries with --query and specify concurrent clients with --concurrency.

Totally artificial but you can use the sleep() function:

select sleep(10);

In the log:

Time                 Id Command    Argument
# Time: 110629 16:19:13
# User@Host: mysql[mysql] @ localhost []
# Query_time: 10.000218  Lock_time: 0.000000 Rows_sent: 1  Rows_examined: 0
SET timestamp=1309389553;
select sleep(10);