Hi,
Most frequently task of DBA is monitor database and which session is active and which is inactive or which one is blocked.
You can use whoIsActive and following script for monitoring all sessions status.
SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED SELECT SPID = er.session_id ,BlkBy = er.blocking_session_id ,ElapsedMS = er.total_elapsed_time ,CPU = er.cpu_time ,IOReads = er.logical_reads + er.reads ,IOWrites = er.writes ,Executions = ec.execution_count ,CommandType = er.command ,ObjectName = OBJECT_SCHEMA_NAME(qt.objectid,dbid) + '.' + OBJECT_NAME(qt.objectid, qt.dbid) ,SQLStatement = SUBSTRING ( qt.text, er.statement_start_offset/2, (CASE WHEN er.statement_end_offset = -1 THEN LEN(CONVERT(nvarchar(MAX), qt.text)) * 2 ELSE er.statement_end_offset END - er.statement_start_offset)/2 ) ,Status = ses.status ,[Login] = ses.login_name ,Host = ses.host_name ,DBName = DB_Name(er.database_id) ,LastWaitType = er.last_wait_type ,StartTime = er.start_time ,Protocol = con.net_transport ,transaction_isolation = CASE ses.transaction_isolation_level WHEN 0 THEN 'Unspecified' WHEN 1 THEN 'Read Uncommitted' WHEN 2 THEN 'Read Committed' WHEN 3 THEN 'Repeatable' WHEN 4 THEN 'Serializable' WHEN 5 THEN 'Snapshot' END ,ConnectionWrites = con.num_writes ,ConnectionReads = con.num_reads ,ClientAddress = con.client_net_address ,Authentication = con.auth_scheme FROM sys.dm_exec_requests er LEFT JOIN sys.dm_exec_sessions ses ON ses.session_id = er.session_id LEFT JOIN sys.dm_exec_connections con ON con.session_id = ses.session_id CROSS APPLY sys.dm_exec_sql_text(er.sql_handle) as qt OUTER APPLY ( SELECT execution_count = MAX(cp.usecounts) FROM sys.dm_exec_cached_plans cp WHERE cp.plan_handle = er.plan_handle ) ec ORDER BY er.blocking_session_id DESC, er.logical_reads + er.reads DESC, er.session_id;
Do you want to learn Microsoft SQL Server DBA Tutorials for Beginners, then read the following articles.
https://ittutorial.org/sql-server-tutorials-microsoft-database-for-beginners/