In this post, I am sharing one script to find bad processes or sessions of Microsoft SQL Server.
Using this script, you can find block process, and which host, application, a user is running with it.

Running this script will tell you which instance of a process is using lots of CPU on the database server. You can use the loginame or hostname columns to identify the person.

SELECT TOP 25
	spid
	,blocked
	,convert(varchar(10),db_name(dbid)) as DBName
	,cpu
	,datediff(second,login_time, getdate()) as Secs
	,convert(float, cpu / datediff(second,login_time, getdate())) as PScore
	,convert(varchar(16), hostname) as Host
	,convert(varchar(50), program_name) as Program
	,convert(varchar(20), loginame) as Login
FROM master..sysprocesses
WHERE datediff(second,login_time, getdate()) > 0 and spid > 50
ORDER BY pscore desc

In the previous post, I have shared important details about SQL Server DBCC INPUTBUFFER and how we can use it to find a lead blocker transaction.

SQL Server: DBCC INPUTBUFFER to find the last statement executed by a SPID

SQL Server 2016 introduced sys.dm_exec_input_buffer which is a extended version of DBCC INPUTBUFFER.
It is also serving the same service like DBCC INPUTBUFFER.

You can build your full query using this new system dmv.

Prepared a script to find the last statement executed by SPID.

SELECT
	der.session_id
	,ib.event_info AS QueryText
FROM sys.dm_exec_requests AS der
JOIN sys.dm_exec_sessions AS des 
	ON des.session_id = der.session_id
CROSS APPLY sys.dm_exec_input_buffer(der.session_id, der.request_id) AS ib
WHERE
	des.is_user_process = 1
GO

Are you SQL Server DBA?
Have you ever faced deadlock situations?
What are your steps to remove a deadlock?
Do you know, how to get the last statement executed by lead blocker transaction?

If you are a SQL DBA, you must know about this.
You can access few related articles:

SQL Server: Database Lock, Deadlock, Block and Isolation Interview Questions and Answers (Day-1)

SQL Server: 8 different ways to Detect a DeadLock in a Database

DBCC INPUTBUFFER:
Using this DBCC command, you can get the last statement executed by a particular SPID which is playing a lead blocker role.

Please do not blindly kill the connections by SPID. You must know the root cause of deadlock and its previous lead blocker transaction.

Prepared a one example demonstration on this.

Create a table with sample data:

CREATE TABLE tbl_Students 
(
	StudID INT
	,StudName VARCHAR(20)
)
GO

INSERT INTO tbl_Students
VALUES 
(1,'Anvesh'),(2,'Neevan')
,(3,'Jeeny'),(4,'Roy');

BEGIN TRANSACTION 
UPDATE tbl_Students SET StudName = 'Meera' 
WHERE StudID = 1
GO

UPDATE tbl_Students SET StudName = 'Anvesh' 
WHERE StudID = 1
GO

SP_WHO2

DBCC INPUTBUFFER (151)

EventType      Parameters EventInfo
-------------- ---------- --------------------
Language Event 0          BEGIN TRANSACTION 
UPDATE tbl_Students SET StudName = 'Meera' 
WHERE StudID = 1

In this post, I am sharing scripts to kill all your running processes or sessions of SQL Server.

DBA always set time of database maintenance activities, but sometimes they find few running sessions so they require closing all connections of a SQL Server Database.

Before executing this script, please take care and verify all running connections and processes otherwise this script will harm to your data.

You require this type of script very occasionally, but I am sharing here because this is also one of the important scripts for SQL DBA.

How to find running sessions or processes in SQL Server?

Script to find Running Process and Session in SQL Server

Command to Kill particular session_id:

KILL 'session_id'

Script to kill multiple sessions:

DECLARE @DatabaseName nvarchar(50)
SET @DatabaseName = 'dbrnd'

DECLARE @SQL varchar(max)
SET @SQL = ''

SELECT @SQL = @SQL + 'Kill ' + Convert(varchar, SPId) + ';'
FROM MASTER..SysProcesses
WHERE DBId = DB_ID(@DatabaseName) AND SPId <> @@SPId

EXEC(@SQL)

Change your database mode from multi-user to single-user:

Once you change the database mode from multi-user to single-user, SQL Server immediately stops all the connections of the database. No one can connect to that database.

The DBA can perform the maintenance activity and after that, they can again change the database mode from single-user to multi-user.

To set Single User:

ALTER DATABASE [Database_Name] SET SINGLE_USER WITH ROLLBACK IMMEDIATE

To set Multi User:

ALTER DATABASE [Database_Name] SET MULTI_USER WITH ROLLBACK IMMEDIATE

In this post, I am sharing one script to find a list of queries which are blocked by other running queries of SQL Server.

DBAs are always seeking for long running queries, most resources consumed query. Using this script DBA can find list of waiting queries which are not under any type of execution.

DBAs can use this query to prevent the deadlock also because long running block transactions can occur a deadlock situation.

SELECT
	dowt.session_id
	,dowt.wait_duration_ms
	,dowt.wait_type
	,dowt.blocking_session_id
	,dese.host_name as HostName
	,der.command
	,der.percent_complete
	,der.cpu_time
	,der.total_elapsed_time
	,der.reads
	,der.writes
	,der.logical_reads
	,der.row_count
	,dest.text AS QueryText
	,dest.dbid AS DatabaseID
	,deqp.query_plan
	,der.plan_handle
FROM sys.dm_os_waiting_tasks as dowt
INNER JOIN sys.dm_exec_sessions as dese
	ON dowt.session_id = dese.session_id
INNER JOIN sys.dm_exec_requests as der
	ON dese.session_id = der.session_id
CROSS APPLY sys.dm_exec_sql_text(der.plan_handle) as dest
CROSS APPLY sys.dm_exec_query_plan(der.plan_handle) as deqp
WHERE dowt.session_id > 50

Here, You can also access few related articles:

SQL Server: Script to find TOP 20 most used or executed SQL Queries

SQL Server: Script to find top 20 running query, which are utilizing more CPU

SQL Server: 8 different ways to Detect a DeadLock in a Database