If you are experiencing slowdowns and delays on Cognos reports on your Unix-based system, the first good place to look is at your ulimit parameters.  To see your ulimit values, enter “ulimit -a” on your Unix system.

time(seconds) unlimited
file(blocks) unlimited
data(kbytes) unlimited
stack(kbytes) 8192
coredump(blocks) unlimited
nofiles(descriptors) 256
memory(kbytes) unlimited

Pay particular attention to your maximum file descriptor, listed above as nofiles(descriptors).  The default value of this item can be quite low, as you can see in this example.  Setting it higher can make significant improvement on your Cognos system.  You can set this value with the Unix command ulimit -n xxxxx (where xxxxx is your desired maximum file descriptor value).

You will find that these ulimit settings are a function of your Unix session, and will revert to default values after you log out.  If you want to make permanent changes to your Cognos ulimit settings you will need to either:

1. Create a script that calls ulimit -n xxxxx command before it calls the cogconfig.sh file for Cognos startup; or
2. Add the ulimit -n xxxxx command to your .profile for the Unix account account in question (open with vi .profile)

For more information on ulimit settings for Cognos, see this IBM article here (this IBM article is specific to AIX and Linux systems).