Multi site with one installation

I made a multi subdomain site with 1 PHPFusion installation, which uses a separate database for each site.

It is V7.03, but can also be V8.xx.

I have multi subdomains like:
www.sub1.mysite.com
www.sub2.mysite.com

On the webserver every subdomain is pointing to the same folder on the webserver.

each site has its own database e.g. databasenames are like mysite_sub1 and mysite_sub2
each site has its own config.php in the root of the site e.g. config_sub1.php and config_sub2.php

In each config.php the settings for the database access are specified for each subdomain.
So in config_sub1.php the name of the database is: mysite_sub1, together with database login credentials, and different cookie prefix to prevent messing up with different login sessions.

In maincore.php I added the following:




and I modified:



to




and



to



I Tested and this is working OK for me.
So now I can run two different sites from one installation, only different databases.

Question is:
Is this a good practice to do?
It probably need some code to prevent $_SERVER['HTTP_HOST'] containing wrong domain name data.

One thing more to do is: there are some cron-jobs executed also, this needs some modification too, to be sure the cron job is executed with the right database.
This can be done by adding a parameter to the cron-job command line, so the con-job php file 'knows' which database to open, or modify the cron-job php file to run through all the databases after each other.