Under some circumstances, you might want to move one or more SharePoint site collections to a different content database. For example, a site collection can outgrow the content database on which it resides, and you would have to move the site collection to a larger content database.
You can move site collections between databases in a SharePoint Server farm by using Microsoft PowerShell.
$siteUrl = Read-Host “Enter Site Collection URL to be moved”
$newDBName
= Read-Host “Enter destination Database Name”
$contentDBInfo
= Get-SPContentDatabase -Site $siteUrl
$oldDBName
= $contentDBInfo.Name
Move-SPSite
-Identity $siteUrl -DestinationDatabase $newDBName
Write-Host
""
Write-Host
"Site collection " $siteUrl "has been moved from "
$oldDBName "to " $newDBName " successfully."
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Create new Database in SQL Managemnet Studio.
In Central Administration add
Database to Web Application.
Central Administration, Content Databases, choose Web Aplication, Add a
content database.
Run PowerShell as Administrator and start the script.
Possible error:
“Cannot complete the copy or merge operation because the database schema
versions are different.”
Sometimes you content databases do not get properly upgraded during the
installation of a cumulative update or service pack. There is a quick an easy
fix. Just use the Upgrade-SPContentDatabase cmdlet to update the content
database.
Upgrade-SPContentDatabase -Identity <content database name>
