Powershell SPSiteDataQuery Debug

clear
$site = Get-SPSite -Identity http://url
$q = New-Object -TypeName microsoft.SharePoint.SPSiteDataQuery
$q.Lists = "<Lists BaseType='1'/>"
$q.ViewFields = "<FieldRef Name='FieldInternalName'/>"
$q.Query = "<Where><Eq><FieldRef Name='FieldInternalName'/><Value Type='Text'>2011-0077</Value></Eq></Where>"
$q.Webs = "<Webs Scope='SiteCollection'/>"
echo $site.RootWeb.GetSiteData($q).Rows.Count