This command returns this error "segmetation fault" after try to upgrade mysql server 3.23 to 4, maybe upgrading the rpm command the problem can be fixed, thanks....

There are ways to rebuild the RPM database, if need be, but RH 8 is ancient, as is MySQL 4. MySQL is up to 5.1 now, and RedHat 8 has long been replaced by FedoraCore, which is up to 11.

This http://www.informatimago.com/linux/rpm-rebuilddb.html will help you with the RPM db rebuild, which MIGHT solve your problem. The man pages for the RPM command are a good resource too. However, I'd strongly suggest upgrading. If your system is that old, you're likely missing LOTS of security related patches, and updated a VERY old piece of software, for just an OLD piece of software, isn't going to get you much.

For long term support you may wish to use Centos instead of Fedora. Fedora only supports any one version for 13months after that you are in the same situation you are with RH8. Centos has a 5 year(plus) support life. Centos is RHEL(RedHat Enterprise Linux) with the logos removed. It is binary compatible with RHEL and is free to download/update(unlike RHEL). To give you an idea how far behind RH8 is, the last update was in 2003.