I have seen this question pop-up in the forums and I think I also got an email from one of my blog readers asking how they can move a site collection from one database to another database.

This can be done via SharePoint 2010 Management Shell [aka PowerShell] and this is what you need to do.

You must have the content database in place [created before you do this operation] for a particular web application and then use the following

Move-SPSite “http://justsharepoint.com/sites/team” –DestinationDatabase “ContentDatabase02”  -confirm:$false

IIS reset

Done. Your site collection is now in ContentDatabase02