The Data Charmer: Introducing MySQL Sandbox

Normal MySQL users are going through a flurry of announcements about new versions that make them salivate ath the thought of what can be done with these new goodies. In November, version 5.0 became generally available, thur ready for production, then version 5.1 entered beta.
Ah! It would be nice if I could just install the new versions and test them. Sometimes, though, you can't do that, because you don't have root access, or you have already an older MySQL server running.
For years, due to my consulting duties, I have maintained several non-conflicting, different versions of MySQL. I did that manually, using some scripts that I have developed and tuned over time. For me it is not a big hassle. I am used to the command line, I wrote the tools, I know what to take care of, it's easy. Not so for some of my co-workers, who need to use the same facilities but lack the same degree of confidence that I got with trial-and-error.
So finally I put together all I did for myself and transferred most of my own knowledge into a Perl script that can create a seamless installation of MySQl 5.0 or 5.1 without need of root access, and without disturbing (or being disturbed by) existing MySQL installations.
I called this tool the MySQL Sandbox and I put it on SourceForge.

With this package, achieving your goal of a separated testing installation is quite simple (provided that you are running Linux or some other Unix, that is):

Download the binaries for the version of MySQL you want to try, or follow Markus Popp's instructions and compile your own.
Unpack MySQL binaries in a convenient place (for the sake of this example, let's say you put it under $HOME/binaries/5.1.10)
Download the latest MySQL Sandbox package and unpack it.
Run the install program, saying where are the binaries

$ ./install.pl --basedir=$HOME/binaries/5.1.10
The MySQL 5 Sandbox,  version 1.1 19-Apr-2006
(C) 2006 Giuseppe Maxia, Stardata s.r.l.

installing with the following parameters:
                  basedir : /home/gmax/binaries/5.1.10
                  binbash : /bin/bash
                conf_file :
             datadir_from : archive
              db_password : datacharmer
                  db_user : datacharmer
                    force : 0
           home_directory : /home/gmax
          install_version : 5.1
                  my_file :
    operating_system_user : gmax
        sandbox_directory : mysql_sandbox
             sandbox_port : 3310
                  verbose : 0
do you agree? ([Y],n)

If you answer "Y", or just press ENTER, the sandbox will create a $HOME/mysql_sandbox directory, and a data directory under it, containing the minimum for your MySQL installation to work.
The destination directory will also contain some shell scripts to start, stop, and use the test server.
Optionally, you can also change the default configuration file by specifying --my_file={small|large|huge} . The sandbox installer will try to locate the sample files from the basedir you indicated, and will merge the basic parameters into your destination file (my.sandbox.cnf)
Once the installation is over, you go to the newly created directory, and start the server:

$ ./start.sh
~/binaries/5.1.10 ~/mysql_sandbox
~/mysql_sandbox
sandbox server started

After that, using the new server is easy.

$ ./use.sh
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1 to server version: 5.1.10-beta-max

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql [localhost] {datacharmer} ((none)) > exit

As you see, there is also a dedicated prompt that may remind you what you are using.
It has been tested in several Linux boxes. Ideally, it should work on every Unix box. Read the docs, or try