Update alerts after DB migration in SharePoint 2010

It is recommended to again set alerts if DB is attached from one web application to other.
In this scenario existing alerts will send URL of old web application

Activate Publishing feature at all site collection through powershell

$feature = Get-SPFeature PublishingSite
$siteCollections = Get-SPSite –WebApplication http://sp2010
$siteCollections | foreach-object {
   Write-Host "Activating" $feature.DisplayName "on" $_.Url
   Enable-SPFeature $feature -Url $_.Url
}