MySql Linux-2.2 max open files limit

I apologise of this is a little bit off topic, but since I have found
that the people on this list
seam to have a very good general knowledge of computer systems I could
not resist
throwing in my question here. I want to increase the MySQL table cash to
hold some
600 tables in the cash. If I read the documentation right I would then
need to have
3x600=1800 open files. Have anyone tried to increase the max number of
open files
per process in a Linux 2.2 kernel ? I haven't figured out which constant
to change.
The include files of a 2.2.6 kernel have the following constants
defined:

"include/linux/fs.h"

   #define NR_OPEN 1024
   #define NR_FILE   4096

"include/linux/limits.h"

  #define NR_OPEN   1024
  #define OPEN_MAX 256


If I run getrlimit() to read max number of open files on a 2.2.6 kernel
I get 1024
(256 on a 2.0.36 kernel) This lead me to think that NR_OPEN is the value
to change
although comments in the limits.h file says its OPEN_MAX. I tried
changing NR_OPEN
to 2048 in both fs.h and limits.h and recompiled the kernel , but the
new kernel didn't boot.
Apparently this is more complicated that I first thought. Does anyone
have any suggestions?
Many thanks in advance (and again I apologize if you think it's off
topic)

--leif
---------------------------------------------------------
Leif Thuresson               Tel:    [phone]
Uppsala University           Fax:    [phone]
The Svedberg Laboratory      E-mail: leif.thuresson@stripped
P.O.Box 533
S-751 21 Uppsala
Sweden