You need to do standard SQL Server database maintenance. There’s nothing about this that’s a Sonarqube issue. The minimum maintenance for a SQL database is:
- Run backups - this allows Shrink to recover space in the transaction logs
- Shrink the database
- Re-index the database - rebuild the indexes to defragment and order/align them
These are all SQL DBA tasks. Do you have a full-time DBA? They should know how to do this.
Google “SQL Server Database Maintenance”. There are any number of writeups on this.