SharePoint deleted large site but released only 65% free space in content database

Question

We have deleted one large share point site collection with space 150 GB through gradual delete job from a large content database size 300 GB.

The job ran for 45 days but released only 100GB free space on the content database. I checked the job status it is completed and there is no references of deleted site in content database sitedeletion table and docstreams table.

Why it is showing only 100 GB free space on SQL content database and how can we reclaim that another 50 GB free space ?

Answer 1

Many activities can create unused space in the database. These activities include running the Windows PowerShell command, and deleting documents, document libraries, lists, list items, and sites. Check official document here.

Here is a good thread about thrink and rebuild index to reduce fragmentation for your reference