Make sure that you have your 'open-files-limit' parameter set to a sane
value in your my.cnf. If you don't have anything set for that limit
the default is extremely low (so low that using views tended to not
work on my dev box). I have been using "open-files-limit = 8192",
however YMMV.
A very easy test to do and see if you hit the limits on the number of
open files for your database configurations and actual number of tables
and databases in it, you can simply do this very simple step:
mysqlcheck -m -A -hYourHost -uYourUsers -pYourPassword
If you reach your limits on the open files, you will see the errors real
quick on the screen when doing a simple tests on it. Then increase your
limits to fit your needs and give yourself room obviously!
This is the easiest test for this limits and many users report the same
error 9 and that's what it is and this way to test for it real quick.
