In this post, I am sharing a script for getting a total number of connected sessions of a SQL Server Database.

There are multiple ways for getting the information of connected users, but I am sharing one of the handy DBA scripts which they can use in their day to day work.

Check the below script:

select
       db_name (resource_database_id) as DatabaseName
       ,count (*) as TotalSessions
from sys.dm_tran_locks
where resource_type = 'DATABASE'
	and db_name (resource_database_id) = 'Database_Name'
group by db_name (resource_database_id)
order by db_name (resource_database_id)

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 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

The PostgreSQL Prepared Statement or Parameterized Statements are always good for specific purpose like: can create Prepared Statement for frequently executing query of a session, It also prevents from SQL Injections.

Prepared Statements are faster for a particular session because It does not require parsing and compiling for each execution. It is only session specific and once a session kill, Prepared Statements automatically destroy.

Here, You can access more on Prepared Statements.

Prepared or Parameterized Statements in Database System

Small demonstration of PostgreSQL Prepared Statement:

Create a table with sample records:

CREATE TABLE tbl_Students 
(
	StudID INTEGER PRIMARY KEY
	,StudName CHARACTER VARYING
	,StudClass CHAR(1)	
);

INSERT INTO tbl_Students 
VALUES (1,'Anvesh','A')
,(2,'Neevan','B'),(3,'Jenny','C')
,(4,'Roy','C'),(5,'Martin','C');

Create a Prepared Statement to SELECT Students data:

PREPARE pre_GetStudents (INT) AS 
SELECT *FROM tbl_Students WHERE StudID = $1;

Execute a Prepared Statement:

EXECUTE pre_GetStudents(2);

System view to check the Prepare statements of session:

SELECT *FROM pg_prepared_statements;