Let’s say that you want to measure something in your database,
and for that you need several operations to happen in parallel.
If you have a capable programming language at your disposal
(Perl, Python, Ruby, PHP, or Java would fit the bill) you can
code a test that sends several transactions in parallel.
But if all you have is the shell and the mysql client, things can
be trickier. Today I needed such a parallel result, and I only
had mysql and bash to accomplish the task.
In the shell, it’s easy to run a loop:
for N in $(seq 1 10)
mysql -h host1 -e "insert into sometable values($N)"
But this does run queries sequentially, and each session will
open and close before the next one starts. Therefore there is no
concurrency at all.[Read more]
Then I thought that the method for parallel execution in the
shell is to run things in the background, and then collect the …