We need to unpublish a complete Publication with thousands of Components and Pages. Usually, we can do it unpublishing all using the Publishing Queue but this action blocks the Queue during various days.
Is there an option to delete a complete Publication from the Content Broker and mark it as unpublished in CM?
You should look at decommissioning the publication target. Here are some links to the documentation. Strictly speaking it's not per publication, but assuming your system is set up in a reasonably standard way, you will achieve the result you want.
Please also note that making any change manually in the CM and Broker database will void your support status.
Clear-TcmPublicationTarget - cmdlet to be used to remove the publishing states from CMS.
I would recommend using TOM.API or Core Service to unpublish the items by triggering transaction as LOW priority to publishing queue to remove the items from Content Broker database. so that normal content editors publishing will not impact.
