Maybe this is a wrong article... talking about memory allocation error !
I've Ubuntu 10.04 !
I'd like to upgrade Mysql version to latest, if it's possible..
I don't know, i've asked you because sometimes there's some incompatibility with Plesk or other software..
Someone has tested it ?
To upgrade i need to do manually by command line ?
What is a necessity for this MySQL upgrade? If everything works well, ask yourself - why would I want any possible problems? It should be done with ubuntu package manager in command line and if you have not enough expirience I recommend you leaving it as is or ask help of experienced Linux/Plesk administrator.
yes you're right ! i've seen that mysql 5.5 has some new features about SQL and for that reason i think to upgrade it but this is not important !
i'll wait that Parallels upgrade it with future Plesk..
Yes, but mysql package is not shipped with Plesk but it only downloads it from original OS vendor repo and it is quite likely it may be outdated there (especially for older OS). If your OS comes with fresh version of mysql, then Plesk would run this mysql.