A quick note for who have the need of installing RMySQL on CentOS (or RHEL).
Given this I went to the RMySQL project page and downloaded both the RMySQL_0.7-5.tar.gz and the (required) DBI_0.2-5.tar.gz packages.
This because installing the R-DBI package provided by the activated repository on my system gave me errors during the actual RMySQL installation.
So, as root – since the installation was needed system-wide – i gave those two following commands:
[root@testing ~]# R CMD INSTALL DBI_0.2-5.tar.gz
[root@testing ~]# R CMD INSTALL RMySQL_0.7-5.tar.gz
Then all the user needed to do was loading into his R environment the new modules!
For future reference: