Powershell: Start-SPAssignment -Global
It allows you to assign a variable to a list of objects and provides you the ability dispose of those objects at any time in the script. You can assign a list of objects, like your SPSite, SPWeb objects and dispose of them when you no longer need them. It is very useful in memory intensive powerhsell applications.
$fdb = Get-SPDatabase –Identity <id of database>
$site= New-Object Microsoft.SharePoint.SPSite (“http://SP2010”)
$list.Fields |select ID, title, internalname| more
In SPQuery you have to use internal Names only.