OM 2007 Cmdlets using the -criteria option
Some information that was obtained from Brian Wren's MMS Cmdshell presentation. http://blogs.technet.com/brianwren/archive/2008/03/11/mms-command-shell-presentation.aspx
When using cmdlets that fetch data in operations Manager 2007 like get-alert, get-event, get-override and many others, use the -criteria option to filter your data. When the -criteria option is used the filter or comparison will be done at the server end and the results will be sent to your cmdshell, thus reducing the amount of processing that your cmdshell has to do. One other thing about criteria, it is case sensitive. For a complete syntax reference on Criteria Expression check out this web page on the SCOM SDK http://msdn2.microsoft.com/en-us/library/bb437603.aspx