ways to reduce the size of the tempdb database in SQL Server without restarting the server
Clearing TempDB: You can clear the contents of the tempdb database by running the following command: DBCC FREEPROCCACHE; DBCC DROPCLEANBUFFERS; This will remove all cached data and stored procedures from memory, which will reduce the size of tempdb. Reduce the number of active sessions: The tempdb database is used to store temporary data for all active sessions. You can reduce the number of active sessions by killing any inactive or idle sessions. Check for long-running transactions: Long-running transactions can cause the tempdb database to grow in size. You can check for long-running transactions by using the following query: SELECT at.transaction_id, at.name, at.transaction_begin_time, DATEDIFF(minute, at.transaction_begin_time, GETDATE()) AS 'Duration', at.isolation_level, ar.session_id, ar.database_id, ar.command, aa.start_time, DATEDIFF(minute, aa.start_time, GETDATE()) AS