SQL Server Queries

### Check currently running queries
reference: https://stackoverflow.com/a/29400789
```
SELECT   SPID       = er.session_id
    ,STATUS         = ses.STATUS
    ,[Login]        = ses.login_name
    ,Host           = ses.host_name
    ,BlkBy          = er.blocking_session_id
    ,DBName         = DB_Name(er.database_id)
    ,CommandType    = er.command
    ,ObjectName     = OBJECT_NAME(st.objectid)
    ,CPUTime        = er.cpu_time
    ,StartTime      = er.start_time
    ,TimeElapsed    = CAST(GETDATE() - er.start_time AS TIME)
    ,SQLStatement   = st.text
FROM    sys.dm_exec_requests er
    OUTER APPLY sys.dm_exec_sql_text(er.sql_handle) st
    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
WHERE   st.text IS NOT NULL
```

### Check currently running jobs
reference: https://stackoverflow.com/a/54684796
```
 WITH
    CTE_Sysession (AgentStartDate)
    AS 
    (
        SELECT MAX(AGENT_START_DATE) AS AgentStartDate FROM MSDB.DBO.SYSSESSIONS
    )   
SELECT sjob.name AS JobName
        ,CASE 
            WHEN SJOB.enabled = 1 THEN 'Enabled'
            WHEN sjob.enabled = 0 THEN 'Disabled'
            END AS JobEnabled
        ,sjob.description AS JobDescription
        ,CASE 
            WHEN ACT.start_execution_date IS NOT NULL AND ACT.stop_execution_date IS NULL  THEN 'Running'
            WHEN ACT.start_execution_date IS NOT NULL AND ACT.stop_execution_date IS NOT NULL AND HIST.run_status = 1 THEN 'Stopped'
            WHEN HIST.run_status = 0 THEN 'Failed'
            WHEN HIST.run_status = 3 THEN 'Canceled'
        END AS JobActivity
        ,DATEDIFF(MINUTE,act.start_execution_date, GETDATE()) DurationMin
        ,hist.run_date AS JobRunDate
        ,run_DURATION/10000 AS Hours
        ,(run_DURATION%10000)/100 AS Minutes 
        ,(run_DURATION%10000)%100 AS Seconds
        ,hist.run_time AS JobRunTime 
        ,hist.run_duration AS JobRunDuration
        ,'tulsql11\dba' AS JobServer
        ,act.start_execution_date AS JobStartDate
        ,act.last_executed_step_id AS JobLastExecutedStep
        ,act.last_executed_step_date AS JobExecutedStepDate
        ,act.stop_execution_date AS JobStopDate
        ,act.next_scheduled_run_date AS JobNextRunDate
        ,sjob.date_created AS JobCreated
        ,sjob.date_modified AS JobModified      
            FROM MSDB.DBO.syssessions AS SYS1
        INNER JOIN CTE_Sysession AS SYS2 ON SYS2.AgentStartDate = SYS1.agent_start_date
        JOIN  msdb.dbo.sysjobactivity act ON act.session_id = SYS1.session_id
        JOIN msdb.dbo.sysjobs sjob ON sjob.job_id = act.job_id
        LEFT JOIN  msdb.dbo.sysjobhistory hist ON hist.job_id = act.job_id AND hist.instance_id = act.job_history_id
        WHERE ACT.start_execution_date IS NOT NULL AND ACT.stop_execution_date IS NULL
        ORDER BY ACT.start_execution_date DESC
```

### Check indexes usage

reference: https://www.mssqltips.com/sqlservertip/1239/how-to-get-index-usage-information-in-sql-server/

```
SELECT
    OBJECT_NAME(S.[OBJECT_ID]) AS [OBJECT NAME], 
    I.[NAME] AS [INDEX NAME], 
    USER_SEEKS, 
    USER_SCANS, 
    USER_LOOKUPS, 
    USER_UPDATES 
FROM
    SYS.DM_DB_INDEX_USAGE_STATS AS S 
    INNER JOIN SYS.INDEXES AS I 
    ON I.[OBJECT_ID] = S.[OBJECT_ID] AND I.INDEX_ID = S.INDEX_ID 
WHERE
    OBJECTPROPERTY(S.[OBJECT_ID],'IsUserTable') = 1
    AND OBJECT_NAME(S.[OBJECT_ID]) like 'table_name_prefix%';
```