SharePoint 2010 - New Feature in already deployed solution does not appear

Yesterday, I have created a new feature in an existing SharePoint 2010 solution.
I wrote my code and added the parts to the feature. When I finished my work, I update the solution as usual with this code:

Update-SPSolution -Identity mysolution.wsp -LiteralPath "C:\C#\_DN\MySolution\MySolution\bin\Debug\mysolution.wsp" -GACDeployment

Next, I went to the site collection features and wanted to activate it, but the feature was not appearing in the site collection feature list. What the ...!?!?

After a short Google search I found a solution for this problem.  We need to execute some commands in the PowerShell (SharePoint 2010 Management Shell):

Install-SPFeature -ScanForFeatures

This command will list all not installed features.
You will find your new feature in this list. Now you can install it with the following command:

Install-SPFeature -AllExistingFeatures

After successful execution of this command your feature will appear.

SharePoint 2010 - Ermittlung der Anzahl Items in einer Site Collection

Für die Ermittlung der Anzahl an Items in einer Site Collection benötigt man nicht mehr als die PowerShell.
Hier ist der Code:

$site = new-object Microsoft.SharePoint.SPSite("portal.domain.com/sites/SiteCollectionName")

$allCount = 0

$sitelists = foreach ($web in $site.AllWebs) { foreach ($list in $web.lists) {$allCount = $allCount + $list.ItemCount}}

$allCount

Ergebnis: