SQL Server常用查询

--1.查看数据库版本信息  

select   @@version  as 'Database Version'

--2.查看所有数据库名称及大小  

exec sp_helpdb  

--3.查看数据库所在机器的操作系统参数  

exec master..xp_msver  

--4.查看数据库启动的参数  

exec sp_configure  

--5.查看数据库启动时间  
select convert(varchar(30),login_time,120)  as 'Database StartTime'

from master..sysprocesses where spid=1  

--6.查看数据库服务器名  

select 'Server Name:'+ltrim(@@servername)  as 'Server Name'

--7.查看数据库实例名  

select 'Instance:'+ltrim(@@servicename)  as 'Instance Name' 

--8.数据库的磁盘空间呢使用信息  

exec sp_spaceused  

--9.日志文件大小及使用情况  

dbcc sqlperf(logspace)  

--10.获取磁盘读写情况  
select   
@@total_read [读取磁盘次数],  
@@total_write [写入磁盘次数],  
@@total_errors [磁盘写入错误数],  

getdate() [当前时间]  

--11.获取I/O工作情况  
select @@io_busy,  
@@timeticks [每个时钟周期对应的微秒数],  
@@io_busy*@@timeticks [I/O操作毫秒数],  

getdate() [当前时间]  

--12.查看CPU活动及工作情况  
select  
@@cpu_busy,  
@@timeticks [每个时钟周期对应的微秒数],  
@@cpu_busy*cast(@@timeticks as float)/1000 [CPU工作时间(秒)],  
@@idle*cast(@@timeticks as float)/1000 [CPU空闲时间(秒)],  

getdate() [当前时间]  

--13.检查锁与等待  

exec sp_lock   

--14.用户和进程信息  
--exec sp_who  

exec sp_who2  

--15.活动用户和进程的信息  

exec sp_who 'active'  

--16.查看所有数据库用户登录信息  
exec sp_helplogins   
  
--17.查看所有数据库用户所属的角色信息  
exec sp_helpsrvrolemember  
  
--18.查看链接服务器  
exec sp_helplinkedsrvlogin  
  
--19.查看远端数据库用户登录信息  
--exec sp_helpremotelogin  
   
--20.获取网络数据包统计信息  
select   
@@pack_received [输入数据包数量],  
@@pack_sent [输出数据包数量],  
@@packet_errors [错误包数量],  
getdate() [当前时间]  
  
--21.检查数据库中的所有对象的分配和机构完整性是否存在错误  
--dbcc checkdb  
  
--22.查询文件组和文件  
select   
    df.[name],df.physical_name,df.[size],df.growth,   
    f.[name][filegroup],f.is_default   
from sys.database_files df join sys.filegroups f   
on df.data_space_id = f.data_space_id   
  
--23.查看数据库中所有表的条数  
select  b.name as tablename ,    
        a.rowcnt as datacount    
from    sysindexes a ,    
        sysobjects b    
where   a.id = b.id    
        and a.indid < 2    
        and objectproperty(b.id, 'IsMSShipped') = 0   
  
--24.得到最耗时的前10条T-SQL语句  
;with maco as     
(       
    select top 10    
        plan_handle,    
        sum(total_worker_time) as total_worker_time ,    
        sum(execution_count) as execution_count ,    
        count(1) as sql_count    
    from sys.dm_exec_query_stats group by plan_handle    
    order by sum(total_worker_time) desc    
)    
select  t.text ,    
        a.total_worker_time ,    
        a.execution_count ,    
        a.sql_count    
from    maco a    
        cross apply sys.dm_exec_sql_text(plan_handle) t  
  
--25.显示所有数据库的日志空间信息  
dbcc sqlperf(logspace)  
  
--26.显示错误信息
exec sp_readerrorlog 0,1,'error'


--27.Look at recent Full backups for the current database 
SELECT TOP (30) bs.machine_name, bs.server_name, bs.database_name AS [Database Name], bs.recovery_model,
CONVERT (BIGINT, bs.backup_size / 1048576 ) AS [Uncompressed Backup Size (MB)],
CONVERT (BIGINT, bs.compressed_backup_size / 1048576 ) AS [Compressed Backup Size (MB)],
CONVERT (NUMERIC (20,2), (CONVERT (FLOAT, bs.backup_size) /
CONVERT (FLOAT, bs.compressed_backup_size))) AS [Compression Ratio], 
DATEDIFF (SECOND, bs.backup_start_date, bs.backup_finish_date) AS [Backup Elapsed Time (sec)],
bs.backup_finish_date AS [Backup Finish Date]
FROM msdb.dbo.backupset AS bs WITH (NOLOCK)
WHERE  DATEDIFF (SECOND, bs.backup_start_date, bs.backup_finish_date) > 0 
AND bs.backup_size > 0
AND bs.[type] = 'D' -- Change to L if you want Log backups
AND database_name = DB_NAME(DB_ID())
ORDER BY bs.backup_finish_date DESC OPTION (RECOMPILE);


--28. Get lock waits for current database (Query 68) (Lock Waits)
SELECT o.name AS [table_name], i.name AS [index_name], ios.index_id, ios.partition_number,
        SUM(ios.row_lock_wait_count) AS [total_row_lock_waits], 
        SUM(ios.row_lock_wait_in_ms) AS [total_row_lock_wait_in_ms],
        SUM(ios.page_lock_wait_count) AS [total_page_lock_waits],
        SUM(ios.page_lock_wait_in_ms) AS [total_page_lock_wait_in_ms],
        SUM(ios.page_lock_wait_in_ms)+ SUM(row_lock_wait_in_ms) AS [total_lock_wait_in_ms]
FROM sys.dm_db_index_operational_stats(DB_ID(), NULL, NULL, NULL) AS ios
INNER JOIN sys.objects AS o WITH (NOLOCK)
ON ios.[object_id] = o.[object_id]
INNER JOIN sys.indexes AS i WITH (NOLOCK)
ON ios.[object_id] = i.[object_id] 
AND ios.index_id = i.index_id
WHERE o.[object_id] > 100
GROUP BY o.name, i.name, ios.index_id, ios.partition_number
HAVING SUM(ios.page_lock_wait_in_ms)+ SUM(row_lock_wait_in_ms) > 0
ORDER BY total_lock_wait_in_ms DESC OPTION (RECOMPILE);


-- This query is helpful for troubleshooting blocking and deadlocking issues


--29.Get Table names, row counts, and compression status for clustered index or heap  (Query 60) (Table Sizes)
SELECT OBJECT_NAME(object_id) AS [ObjectName], 
SUM(Rows) AS [RowCount], data_compression_desc AS [CompressionType]
FROM sys.partitions WITH (NOLOCK)
WHERE index_id < 2 --ignore the partitions from the non-clustered index if any
AND OBJECT_NAME(object_id) NOT LIKE N'sys%'
AND OBJECT_NAME(object_id) NOT LIKE N'queue_%' 
AND OBJECT_NAME(object_id) NOT LIKE N'filestream_tombstone%' 
AND OBJECT_NAME(object_id) NOT LIKE N'fulltext%'
AND OBJECT_NAME(object_id) NOT LIKE N'ifts_comp_fragment%'
AND OBJECT_NAME(object_id) NOT LIKE N'filetable_updates%'
AND OBJECT_NAME(object_id) NOT LIKE N'xml_index_nodes%'
GROUP BY object_id, data_compression_desc
ORDER BY SUM(Rows) DESC OPTION (RECOMPILE);


-- 30.Gives you an idea of table sizes, and possible data compression opportunities
-- When was SQL Server installed  (Query 2) (SQL Server Install Date)  
SELECT @@SERVERNAME AS [Server Name], create_date AS [SQL Server Install Date] 
FROM sys.server_principals WITH (NOLOCK)
WHERE name = N'NT AUTHORITY\SYSTEM'
OR name = N'NT AUTHORITY\NETWORK SERVICE' OPTION (RECOMPILE);
-- Tells you the date and time that SQL Server was installed
-- It is a good idea to know how old your instance is


--31. 获取服务器属性 
SELECT SERVERPROPERTY('MachineName') AS [MachineName], SERVERPROPERTY('ServerName') AS [ServerName],  
SERVERPROPERTY('InstanceName') AS [Instance], SERVERPROPERTY('IsClustered') AS [IsClustered], 
SERVERPROPERTY('ComputerNamePhysicalNetBIOS') AS [ComputerNamePhysicalNetBIOS], 
SERVERPROPERTY('Edition') AS [Edition], SERVERPROPERTY('ProductLevel') AS [ProductLevel], 
SERVERPROPERTY('ProductVersion') AS [ProductVersion], SERVERPROPERTY('ProcessID') AS [ProcessID],
SERVERPROPERTY('Collation') AS [Collation], SERVERPROPERTY('IsFullTextInstalled') AS [IsFullTextInstalled], 
SERVERPROPERTY('IsIntegratedSecurityOnly') AS [IsIntegratedSecurityOnly],
SERVERPROPERTY('IsHadrEnabled') AS [IsHadrEnabled], SERVERPROPERTY('HadrManagerStatus') AS [HadrManagerStatus];
-- This gives you a lot of useful information about your instance of SQL Server,


--32. Get SQL Server Agent jobs and Category information  
SELECT sj.name AS [JobName], sj.[description] AS [JobDescription], SUSER_SNAME(sj.owner_sid) AS [JobOwner],
sj.date_created, sj.[enabled], sj.notify_email_operator_id, sj.notify_level_email, sc.name AS [CategoryName],
js.next_run_date, js.next_run_time
FROM msdb.dbo.sysjobs AS sj WITH (NOLOCK)
INNER JOIN msdb.dbo.syscategories AS sc WITH (NOLOCK)
ON sj.category_id = sc.category_id
LEFT OUTER JOIN msdb.dbo.sysjobschedules AS js WITH (NOLOCK)
ON sj.job_id = js.job_id
ORDER BY sj.name OPTION (RECOMPILE);




--33. 从注册表获取CPU描述   
EXEC sys.xp_instance_regread N'HKEY_LOCAL_MACHINE', N'HARDWARE\DESCRIPTION\System\CentralProcessor\0', N'ProcessorNameString';


--34. 配置值  (Configuration Values)
SELECT name, value, value_in_use, minimum, maximum, [description], is_dynamic, is_advanced
FROM sys.configurations WITH (NOLOCK)
ORDER BY name OPTION (RECOMPILE);


--35.Database Filenames and Paths
SELECT DB_NAME([database_id]) AS [Database Name], 
       [file_id], name, physical_name, type_desc, state_desc,
       is_percent_growth, growth,
       CONVERT(bigint, growth/128.0) AS [Growth in MB], 
       CONVERT(bigint, size/128.0) AS [Total Size in MB]
FROM sys.master_files WITH (NOLOCK)
WHERE [database_id] > 4 
AND [database_id] <> 32767
OR [database_id] = 2
ORDER BY DB_NAME([database_id]) OPTION (RECOMPILE);




--36.IO Stalls by File
SELECT DB_NAME(fs.database_id) AS [Database Name], CAST(fs.io_stall_read_ms/(1.0 + fs.num_of_reads) AS NUMERIC(10,1)) AS [avg_read_stall_ms],
CAST(fs.io_stall_write_ms/(1.0 + fs.num_of_writes) AS NUMERIC(10,1)) AS [avg_write_stall_ms],
CAST((fs.io_stall_read_ms + fs.io_stall_write_ms)/(1.0 + fs.num_of_reads + fs.num_of_writes) AS NUMERIC(10,1)) AS [avg_io_stall_ms],
CONVERT(DECIMAL(18,2), mf.size/128.0) AS [File Size (MB)], mf.physical_name, mf.type_desc, fs.io_stall_read_ms, fs.num_of_reads, 
fs.io_stall_write_ms, fs.num_of_writes, fs.io_stall_read_ms + fs.io_stall_write_ms AS [io_stalls], fs.num_of_reads + fs.num_of_writes AS [total_io]
FROM sys.dm_io_virtual_file_stats(null,null) AS fs
INNER JOIN sys.master_files AS mf WITH (NOLOCK)
ON fs.database_id = mf.database_id
AND fs.[file_id] = mf.[file_id]
ORDER BY avg_io_stall_ms DESC OPTION (RECOMPILE);


-- Helps determine which database files on the entire instance have the most I/O bottlenecks
-- This can help you decide whether certain LUNs are overloaded and whether you might
-- want to move some files to a different location or perhaps improve your I/O performance




--37.Missing Indexes All Databases
SELECT CONVERT(decimal(18,2), user_seeks * avg_total_user_cost * (avg_user_impact * 0.01)) AS [index_advantage], 
migs.last_user_seek, mid.[statement] AS [Database.Schema.Table],
mid.equality_columns, mid.inequality_columns, mid.included_columns,
migs.unique_compiles, migs.user_seeks, migs.avg_total_user_cost, migs.avg_user_impact
FROM sys.dm_db_missing_index_group_stats AS migs WITH (NOLOCK)
INNER JOIN sys.dm_db_missing_index_groups AS mig WITH (NOLOCK)
ON migs.group_handle = mig.index_group_handle
INNER JOIN sys.dm_db_missing_index_details AS mid WITH (NOLOCK)
ON mig.index_handle = mid.index_handle
ORDER BY index_advantage DESC OPTION (RECOMPILE);


-- Getting missing index information for all of the databases on the instance is very useful
-- Look at last user seek time, number of user seeks to help determine source and importance
-- Also look at avg_user_impact and avg_total_user_cost to help determine importance
-- SQL Server is overly eager to add included columns, so beware
-- Do not just blindly add indexes that show up from this query!!!




--38.CPU Usage by Database 
WITH DB_CPU_Stats
AS
(SELECT pa.DatabaseID, DB_Name(pa.DatabaseID) AS [Database Name], SUM(qs.total_worker_time/1000) AS [CPU_Time_Ms]
 FROM sys.dm_exec_query_stats AS qs WITH (NOLOCK)
 CROSS APPLY (SELECT CONVERT(int, value) AS [DatabaseID] 
              FROM sys.dm_exec_plan_attributes(qs.plan_handle)
              WHERE attribute = N'dbid') AS pa
 GROUP BY DatabaseID)
SELECT ROW_NUMBER() OVER(ORDER BY [CPU_Time_Ms] DESC) AS [CPU Rank],
       [Database Name], [CPU_Time_Ms] AS [CPU Time (ms)], 
       CAST([CPU_Time_Ms] * 1.0 / SUM([CPU_Time_Ms]) OVER() * 100.0 AS DECIMAL(5, 2)) AS [CPU Percent]
FROM DB_CPU_Stats
WHERE DatabaseID <> 32767 -- ResourceDB
ORDER BY [CPU Rank] OPTION (RECOMPILE);


-- Helps determine which database is using the most CPU resources on the instance


--39. Total  I/O Usage by Database
WITH Aggregate_IO_Statistics
AS
(SELECT DB_NAME(database_id) AS [Database Name],
CAST(SUM(num_of_bytes_read + num_of_bytes_written)/1048576 AS DECIMAL(12, 2)) AS io_in_mb
FROM sys.dm_io_virtual_file_stats(NULL, NULL) AS [DM_IO_STATS]
GROUP BY database_id)
SELECT ROW_NUMBER() OVER(ORDER BY io_in_mb DESC) AS [I/O Rank], [Database Name], io_in_mb AS [Total I/O (MB)],
       CAST(io_in_mb/ SUM(io_in_mb) OVER() * 100.0 AS DECIMAL(5,2)) AS [I/O Percent]
FROM Aggregate_IO_Statistics
ORDER BY [I/O Rank] OPTION (RECOMPILE);


-- Helps determine which database is using the most I/O resources on the instance


--40.Total Buffer Usage by Database 
-- This make take some time to run on a busy instance
WITH AggregateBufferPoolUsage
AS
(SELECT DB_NAME(database_id) AS [Database Name],
CAST(COUNT(*) * 8/1024.0 AS DECIMAL (10,2))  AS [CachedSize]
FROM sys.dm_os_buffer_descriptors WITH (NOLOCK)
WHERE database_id <> 32767 -- ResourceDB
GROUP BY DB_NAME(database_id))
SELECT ROW_NUMBER() OVER(ORDER BY CachedSize DESC) AS [Buffer Pool Rank], [Database Name], CachedSize AS [Cached Size (MB)],
       CAST(CachedSize / SUM(CachedSize) OVER() * 100.0 AS DECIMAL(5,2)) AS [Buffer Pool Percent]
FROM AggregateBufferPoolUsage
ORDER BY [Buffer Pool Rank] OPTION (RECOMPILE);


-- Tells you how much memory (in the buffer pool) 
-- is being used by each database on the instance




--41. Top Waits 
WITH [Waits] 
AS (SELECT wait_type, wait_time_ms/ 1000.0 AS [WaitS],
          (wait_time_ms - signal_wait_time_ms) / 1000.0 AS [ResourceS],
           signal_wait_time_ms / 1000.0 AS [SignalS],
           waiting_tasks_count AS [WaitCount],
           100.0 *  wait_time_ms / SUM (wait_time_ms) OVER() AS [Percentage],
           ROW_NUMBER() OVER(ORDER BY wait_time_ms DESC) AS [RowNum]
    FROM sys.dm_os_wait_stats WITH (NOLOCK)
    WHERE [wait_type] NOT IN (
        N'BROKER_EVENTHANDLER', N'BROKER_RECEIVE_WAITFOR', N'BROKER_TASK_STOP',
        N'BROKER_TO_FLUSH', N'BROKER_TRANSMITTER', N'CHECKPOINT_QUEUE',
        N'CHKPT', N'CLR_AUTO_EVENT', N'CLR_MANUAL_EVENT', N'CLR_SEMAPHORE',
        N'DBMIRROR_DBM_EVENT', N'DBMIRROR_EVENTS_QUEUE', N'DBMIRROR_WORKER_QUEUE',
        N'DBMIRRORING_CMD', N'DIRTY_PAGE_POLL', N'DISPATCHER_QUEUE_SEMAPHORE',
        N'EXECSYNC', N'FSAGENT', N'FT_IFTS_SCHEDULER_IDLE_WAIT', N'FT_IFTSHC_MUTEX',
        N'HADR_CLUSAPI_CALL', N'HADR_FILESTREAM_IOMGR_IOCOMPLETION', N'HADR_LOGCAPTURE_WAIT', 
        N'HADR_NOTIFICATION_DEQUEUE', N'HADR_TIMER_TASK', N'HADR_WORK_QUEUE',
        N'KSOURCE_WAKEUP', N'LAZYWRITER_SLEEP', N'LOGMGR_QUEUE', N'ONDEMAND_TASK_QUEUE',
        N'PWAIT_ALL_COMPONENTS_INITIALIZED', N'QDS_PERSIST_TASK_MAIN_LOOP_SLEEP',
        N'QDS_CLEANUP_STALE_QUERIES_TASK_MAIN_LOOP_SLEEP', N'REQUEST_FOR_DEADLOCK_SEARCH',
        N'RESOURCE_QUEUE', N'SERVER_IDLE_CHECK', N'SLEEP_BPOOL_FLUSH', N'SLEEP_DBSTARTUP',
        N'SLEEP_DCOMSTARTUP', N'SLEEP_MASTERDBREADY', N'SLEEP_MASTERMDREADY',
        N'SLEEP_MASTERUPGRADED', N'SLEEP_MSDBSTARTUP', N'SLEEP_SYSTEMTASK', N'SLEEP_TASK',
        N'SLEEP_TEMPDBSTARTUP', N'SNI_HTTP_ACCEPT', N'SP_SERVER_DIAGNOSTICS_SLEEP',
        N'SQLTRACE_BUFFER_FLUSH', N'SQLTRACE_INCREMENTAL_FLUSH_SLEEP', N'SQLTRACE_WAIT_ENTRIES',
        N'WAIT_FOR_RESULTS', N'WAITFOR', N'WAITFOR_TASKSHUTDOWN', N'WAIT_XTP_HOST_WAIT',
        N'WAIT_XTP_OFFLINE_CKPT_NEW_LOG', N'WAIT_XTP_CKPT_CLOSE', N'XE_DISPATCHER_JOIN',
        N'XE_DISPATCHER_WAIT', N'XE_TIMER_EVENT')
    AND waiting_tasks_count > 0)
SELECT
    MAX (W1.wait_type) AS [WaitType],
    CAST (MAX (W1.WaitS) AS DECIMAL (16,2)) AS [Wait_Sec],
    CAST (MAX (W1.ResourceS) AS DECIMAL (16,2)) AS [Resource_Sec],
    CAST (MAX (W1.SignalS) AS DECIMAL (16,2)) AS [Signal_Sec],
    MAX (W1.WaitCount) AS [Wait Count],
    CAST (MAX (W1.Percentage) AS DECIMAL (5,2)) AS [Wait Percentage],
    CAST ((MAX (W1.WaitS) / MAX (W1.WaitCount)) AS DECIMAL (16,4)) AS [AvgWait_Sec],
    CAST ((MAX (W1.ResourceS) / MAX (W1.WaitCount)) AS DECIMAL (16,4)) AS [AvgRes_Sec],
    CAST ((MAX (W1.SignalS) / MAX (W1.WaitCount)) AS DECIMAL (16,4)) AS [AvgSig_Sec]
FROM Waits AS W1
INNER JOIN Waits AS W2
ON W2.RowNum <= W1.RowNum
GROUP BY W1.RowNum
HAVING SUM (W2.Percentage) - MAX (W1.Percentage) < 99 -- percentage threshold
OPTION (RECOMPILE);


 




--42.Signal Waits 
SELECT CAST(100.0 * SUM(signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [% Signal (CPU) Waits],
CAST(100.0 * SUM(wait_time_ms - signal_wait_time_ms) / SUM (wait_time_ms) AS NUMERIC(20,2)) AS [% Resource Waits]
FROM sys.dm_os_wait_stats WITH (NOLOCK)
WHERE wait_type NOT IN (
        N'BROKER_EVENTHANDLER', N'BROKER_RECEIVE_WAITFOR', N'BROKER_TASK_STOP',
        N'BROKER_TO_FLUSH', N'BROKER_TRANSMITTER', N'CHECKPOINT_QUEUE',
        N'CHKPT', N'CLR_AUTO_EVENT', N'CLR_MANUAL_EVENT', N'CLR_SEMAPHORE',
        N'DBMIRROR_DBM_EVENT', N'DBMIRROR_EVENTS_QUEUE', N'DBMIRROR_WORKER_QUEUE',
        N'DBMIRRORING_CMD', N'DIRTY_PAGE_POLL', N'DISPATCHER_QUEUE_SEMAPHORE',
        N'EXECSYNC', N'FSAGENT', N'FT_IFTS_SCHEDULER_IDLE_WAIT', N'FT_IFTSHC_MUTEX',
        N'HADR_CLUSAPI_CALL', N'HADR_FILESTREAM_IOMGR_IOCOMPLETION', N'HADR_LOGCAPTURE_WAIT', 
        N'HADR_NOTIFICATION_DEQUEUE', N'HADR_TIMER_TASK', N'HADR_WORK_QUEUE',
        N'KSOURCE_WAKEUP', N'LAZYWRITER_SLEEP', N'LOGMGR_QUEUE', N'ONDEMAND_TASK_QUEUE',
        N'PWAIT_ALL_COMPONENTS_INITIALIZED', N'QDS_PERSIST_TASK_MAIN_LOOP_SLEEP',
        N'QDS_CLEANUP_STALE_QUERIES_TASK_MAIN_LOOP_SLEEP', N'REQUEST_FOR_DEADLOCK_SEARCH',
        N'RESOURCE_QUEUE', N'SERVER_IDLE_CHECK', N'SLEEP_BPOOL_FLUSH', N'SLEEP_DBSTARTUP',
        N'SLEEP_DCOMSTARTUP', N'SLEEP_MASTERDBREADY', N'SLEEP_MASTERMDREADY',
        N'SLEEP_MASTERUPGRADED', N'SLEEP_MSDBSTARTUP', N'SLEEP_SYSTEMTASK', N'SLEEP_TASK',
        N'SLEEP_TEMPDBSTARTUP', N'SNI_HTTP_ACCEPT', N'SP_SERVER_DIAGNOSTICS_SLEEP',
        N'SQLTRACE_BUFFER_FLUSH', N'SQLTRACE_INCREMENTAL_FLUSH_SLEEP', N'SQLTRACE_WAIT_ENTRIES',
        N'WAIT_FOR_RESULTS', N'WAITFOR', N'WAITFOR_TASKSHUTDOWN', N'WAIT_XTP_HOST_WAIT',
        N'WAIT_XTP_OFFLINE_CKPT_NEW_LOG', N'WAIT_XTP_CKPT_CLOSE', N'XE_DISPATCHER_JOIN',
        N'XE_DISPATCHER_WAIT', N'XE_TIMER_EVENT') OPTION (RECOMPILE);


-- Signal Waits above 10-15% is usually a confirming sign of CPU pressure
-- Cumulative wait stats are not as useful on an idle instance that is not under load or performance pressure
-- Resource waits are non-CPU related waits




--43.Connection Counts 
SELECT login_name, [program_name], COUNT(session_id) AS [session_count] 
FROM sys.dm_exec_sessions WITH (NOLOCK)
GROUP BY login_name, [program_name]
ORDER BY COUNT(session_id) DESC OPTION (RECOMPILE);


-- This can help characterize your workload and
-- determine whether you are seeing a normal level of activity




-- 44.Connection Counts by IP Address
SELECT ec.client_net_address, es.[program_name], es.[host_name], es.login_name, 
COUNT(ec.session_id) AS [connection count] 
FROM sys.dm_exec_sessions AS es WITH (NOLOCK) 
INNER JOIN sys.dm_exec_connections AS ec WITH (NOLOCK) 
ON es.session_id = ec.session_id 
GROUP BY ec.client_net_address, es.[program_name], es.[host_name], es.login_name  
ORDER BY ec.client_net_address, es.[program_name] OPTION (RECOMPILE);


-- This helps you figure where your database load is coming from
-- and verifies connectivity from other machines


--45.Top Worker Time Queries 
SELECT TOP(50) DB_NAME(t.[dbid]) AS [Database Name], LEFT(t.[text], 255) AS [Short Query Text],  
qs.total_worker_time AS [Total Worker Time], qs.min_worker_time AS [Min Worker Time],
qs.total_worker_time/qs.execution_count AS [Avg Worker Time], 
qs.max_worker_time AS [Max Worker Time], qs.execution_count AS [Execution Count], 
qs.total_elapsed_time/qs.execution_count AS [Avg Elapsed Time], 
qs.total_logical_reads/qs.execution_count AS [Avg Logical Reads], 
qs.total_physical_reads/qs.execution_count AS [Avg Physical Reads], qs.creation_time AS [Creation Time]
--, t.[text] AS [Query Text], qp.query_plan AS [Query Plan] -- uncomment out these columns if not copying results to Excel
FROM sys.dm_exec_query_stats AS qs WITH (NOLOCK)
CROSS APPLY sys.dm_exec_sql_text(plan_handle) AS t 
CROSS APPLY sys.dm_exec_query_plan(plan_handle) AS qp 
ORDER BY qs.total_worker_time DESC OPTION (RECOMPILE);




-- Helps you find the most expensive queries from a CPU perspective across the entire instance
--46.System Memory 
SELECT total_physical_memory_kb/1024 AS [Physical Memory (MB)], 
       available_physical_memory_kb/1024 AS [Available Memory (MB)], 
total_page_file_kb/1024 AS [Total Page File (MB)], 
       available_page_file_kb/1024 AS [Available Page File (MB)], 
       system_cache_kb/1024 AS [System Cache (MB)],
       system_memory_state_desc AS [System Memory State]
FROM sys.dm_os_sys_memory WITH (NOLOCK) OPTION (RECOMPILE);


-- You want to see "Available physical memory is high"
-- This indicates that you are not under external memory pressure