數據庫鏈接狀況查詢

--sp_who 能夠指定數據庫名，查詢指定數據庫的鏈接狀況
sp_who 
go
select  DB_NAME(database_id) dbname, login_name, t1.session_id, t1.request_id, t2.status, t1.start_time, host_name
from    sys.dm_exec_requests t1
        inner join sys.dm_exec_sessions t2 on t1.session_id = t2.session_id
go
--包含正在 Microsoft SQL Server 實例上運行的進程的相關信息。這些進程能夠是客戶端進程或系統進程。若要訪問 sysprocesses，您必須位於 master 數據庫上下文中，或者必須使用由三部分構成的名稱 master.dbo.sysprocesses。
select * from sys.sysprocesses

--查詢指定數據庫的鏈接狀況
select  *
from    [Master].[dbo].[SYSPROCESSES]
where   [DBID] in ( select  [DBID]
                    from    [Master].[dbo].[SYSDATABASES]
                    where name='bpm'
                     )
go

---數據庫系統全部請求狀況
select  s.session_id, s.status, db_name(r.database_id) as database_name, s.login_name, s.login_time, s.host_name,
        c.client_net_address, c.client_tcp_port, s.program_name, r.cpu_time, r.reads, r.writes, c.num_reads,
        c.num_writes, s.client_interface_name, s.last_request_start_time, s.last_request_end_time, c.connect_time,
        c.net_transport, c.net_packet_size, r.start_time, r.status, r.command, r.blocking_session_id, r.wait_type,
        r.wait_time, r.last_wait_type, r.wait_resource, r.open_transaction_count, r.percent_complete,
        r.granted_query_memory
from    Sys.dm_exec_requests r with ( nolock )
        right outer join Sys.dm_exec_sessions s with ( nolock ) on r.session_id = s.session_id
        right outer join Sys.dm_exec_connections c with ( nolock ) on s.session_id = c.session_id
--where   s.session_id > 50
order by s.login_time

go

---哪一個用戶鏈接數最多：
select  login_name, COUNT(0) user_count
from    Sys.dm_exec_requests r with ( nolock )
        right outer join Sys.dm_exec_sessions s with ( nolock ) on r.session_id = s.session_id
        right outer join Sys.dm_exec_connections c with ( nolock ) on s.session_id = c.session_id
where   s.session_id > 50
group by login_name
order by 2 desc

go
---哪臺機器發起到數據庫的鏈接數最多：
select  s.host_name, c.client_net_address, COUNT(0) host_count
from    Sys.dm_exec_requests r with ( nolock )
        right outer join Sys.dm_exec_sessions s with ( nolock ) on r.session_id = s.session_id
        right outer join Sys.dm_exec_connections c with ( nolock ) on s.session_id = c.session_id
where   s.session_id > 50
group by host_name, client_net_address 

go

--進程狀態
select  s.status, COUNT(0) host_count
from    Sys.dm_exec_requests r with ( nolock )
        right outer join Sys.dm_exec_sessions s with ( nolock ) on r.session_id = s.session_id
        right outer join Sys.dm_exec_connections c with ( nolock ) on s.session_id = c.session_id
where   s.session_id > 50
group by s.status
order by 2 desc

go

--查看數據庫阻塞狀況
select  t1.resource_type as [lock type], db_name(resource_database_id) as [database],
        t1.resource_associated_entity_id as [blk object], t1.request_mode as [lock req]                          -- lock requested    
        , t1.request_session_id as [waiter sid]                      -- spid of waiter    
        , t2.wait_duration_ms as [wait time],
        ( select    text
          from      sys.dm_exec_requests as r with ( nolock ) --- get sql for waiter    
                    cross apply sys.dm_exec_sql_text(r.sql_handle)
          where     r.session_id = t1.request_session_id
        ) as waiter_batch,
        ( select    substring(qt.text, r.statement_start_offset / 2,
                              ( case when r.statement_end_offset = -1 then len(convert(nvarchar(max), qt.text)) * 2
                                     else r.statement_end_offset
                                end - r.statement_start_offset ) / 2 + 1)
          from      sys.dm_exec_requests as r with ( nolock )
                    cross apply sys.dm_exec_sql_text(r.sql_handle) as qt
          where     r.session_id = t1.request_session_id
        ) as waiter_stmt    --- statement executing now    
        , t2.blocking_session_id as [blocker sid]                --- spid of blocker    
        , ( select  text
            from    sys.sysprocesses as p with ( nolock ) --- get sql for blocker    
                    cross apply sys.dm_exec_sql_text(p.sql_handle)
            where   p.spid = t2.blocking_session_id
          ) as blocker_stmt, getdate() time
from    sys.dm_tran_locks as t1 with ( nolock ) ,
        sys.dm_os_waiting_tasks as t2 with ( nolock )
where   t1.lock_owner_address = t2.resource_address

go

select  db_name(r.database_id) as database_name, COUNT(0) host_count
from    Sys.dm_exec_requests r with ( nolock )
        right outer join Sys.dm_exec_sessions s with ( nolock ) on r.session_id = s.session_id
        right outer join Sys.dm_exec_connections c with ( nolock ) on s.session_id = c.session_id
where   s.session_id > 50
group by r.database_id
order by 2 desc

go

--查看阻塞其餘進程的進程（阻塞源頭）
select  t2.blocking_session_id,COUNT(0) counts
from sys.dm_tran_locks as t1 with(nolock) , sys.dm_os_waiting_tasks as t2 with(nolock)    
where t1.lock_owner_address = t2.resource_address
group by blocking_session_id
order by 2

go
--被阻塞時間最長的進程
select top 10
        t1.resource_type as [lock type], db_name(resource_database_id) as [database],
        t1.resource_associated_entity_id as [blk object], t1.request_mode as [lock req]                          -- lock requested    
        , t1.request_session_id as [waiter sid]                      -- spid of waiter    
        , t2.wait_duration_ms as [wait time],
        ( select    text
          from      sys.dm_exec_requests as r with ( nolock ) --- get sql for waiter    
                    cross apply sys.dm_exec_sql_text(r.sql_handle)
          where     r.session_id = t1.request_session_id
        ) as waiter_batch,
        ( select    substring(qt.text, r.statement_start_offset / 2,
                              ( case when r.statement_end_offset = -1 then len(convert(nvarchar(max), qt.text)) * 2
                                     else r.statement_end_offset
                                end - r.statement_start_offset ) / 2 + 1)
          from      sys.dm_exec_requests as r with ( nolock )
                    cross apply sys.dm_exec_sql_text(r.sql_handle) as qt
          where     r.session_id = t1.request_session_id
        ) as waiter_stmt    --- statement executing now    
        , t2.blocking_session_id as [blocker sid]                --- spid of blocker    
        , ( select  text
            from    sys.sysprocesses as p with ( nolock ) --- get sql for blocker    
                    cross apply sys.dm_exec_sql_text(p.sql_handle)
            where   p.spid = t2.blocking_session_id
          ) as blocker_stmt, getdate() time
from    sys.dm_tran_locks as t1 with ( nolock ) ,
        sys.dm_os_waiting_tasks as t2 with ( nolock )
where   t1.lock_owner_address = t2.resource_address
order by t2.wait_duration_ms desc