我一直在学习有关 sql server 中动态管理视图的更多信息，因为我们在工作中遇到了一些性能问题。也许这是看待事物的错误方式，但可用的工具似乎......它们似乎不像我想要的那样灵活。
我希望能够找出以下我有示例的内容。
哪些查询的运行速度比正常情况慢 20% 以上？以下 ...
--displays regarding about procedures that are currently taking longer to execute by more than 20% over the average.
;
with data as (
select s.plan_handle
, db.name
, ObjectName = OBJECT_NAME(t.objectid, t.dbid )
, PlanCompileDate = s.creation_time
, PlanExecutionCount = execution_count
, AvgElapsedSeconds = ( total_elapsed_time/ CAST( 1000000 as float(15) ) ) / CAST( s.execution_count as float(15) )
, LastElapsedSeconds = last_elapsed_time / CAST( 1000000 as float(38) )
, LeastElapsedSeconds = min_elapsed_time / CAST( 1000000 as float(15) )
, MostElapsedSeconds = max_elapsed_time / CAST( 1000000 as float(15) )
, LastExecPercentageDevTime = (( ( s.total_elapsed_time / cast(s.execution_count as float(15) ) ) - s.last_elapsed_time ) / ( case s.last_elapsed_time when 0 then -1.00 else ( s.total_elapsed_time / cast( s.execution_count as float(15) ) ) end ) ) * -100
-- 0.00532225
, AvgRowsReturned = total_rows / CAST( s.execution_count as float )
, LastRowsReturned = last_rows
, LeastRowsReturned = min_rows
, MostRowsReturned = max_rows
, LastExecPercentageDevRows = (( ( s.total_rows / cast(s.execution_count as float ) ) - s.last_rows) / ( case s.last_rows when 0 then -1.00 else ( s.total_rows / cast( s.execution_count as float ) ) end ) ) * -100
, AvgCPUTime = s.total_worker_time / CAST( s.execution_count as float )
, LastCPUTime = s.last_worker_time
, LeastCPUTime = min_worker_time
, MostCPUTime = max_worker_time
, LastExecPercentageDevCPUTime = (( ( s.total_worker_time / cast(s.execution_count as float ) ) - s.last_worker_time ) / ( case s.last_worker_time when 0 then -1.00 else ( s.total_worker_time / cast( s.execution_count as float ) ) end ) ) * -100
, AvgPhysicalReads = s.total_physical_reads / CAST( s.execution_count as float )
, LastPhysicalReads = s.last_physical_reads
, LeastPhysicalReads = s.min_physical_reads
, MostPhysicalReads = s.max_physical_reads
, LastExecPercentageDevPhysicalReads = (( ( s.total_physical_reads / cast(s.execution_count as float ) ) - s.last_physical_reads ) / ( case s.last_physical_reads when 0 then -1.00 else ( s.total_physical_reads / cast( s.execution_count as float ) ) end ) ) * -100
, AvgLogicalReads = s.total_logical_reads / CAST( s.execution_count as float )
, LastLogicalReads = s.last_logical_reads
, LeastLogicalReads = s.min_logical_reads
, MostLogicalReads = s.max_logical_reads
, LastExecPercentageDevLogicalReads = (( ( s.total_logical_reads / cast(s.execution_count as float ) ) - s.last_logical_reads ) / ( case s.last_logical_reads when 0 then -1.00 else ( s.total_logical_reads / cast( s.execution_count as float ) ) end ) ) * -100
, AvgLogicalWrites = s.total_logical_Writes / CAST( s.execution_count as float )
, LastLogicalWrites = s.last_logical_Writes
, LeastLogicalWrites = s.min_logical_Writes
, MostLogicalWrites = s.max_logical_Writes
, LastExecPercentageDevLogicalWrites = (( ( s.total_logical_writes / cast(s.execution_count as float ) ) - s.last_logical_writes ) / ( case s.last_logical_writes when 0 then -1.00 else ( s.total_logical_writes / cast( s.execution_count as float ) ) end ) ) * -100
, t.text
, t.number
, t.objectid
, s.query_hash
--, s.*
FROM sys.dm_exec_query_stats AS s
CROSS APPLY sys.dm_exec_sql_text(s.sql_handle) AS t
LEFT JOIN sys.databases AS DB
ON t.dbid = DB.database_id
)
select *
from data
where LastExecPercentageDevTime > 20 and -- changed by at least 20%
PlanExecutionCount > 10 and -- executed more than 10 times
LastElapsedSeconds != 0 -- we don't care about queries that executed quickly
order by LastExecPercentageDevTime desc
当有阻塞时，我希望能够确定正在执行阻塞的查询，也许它的依赖对象是什么。
我相信以下内容可以找到执行阻塞的查询
-- What queries are the source of all the blocking.
with blockingSessions as(
select session_id,blocking_session_id
from sys.dm_exec_requests
where blocking_session_id > 0
), causal as(
select blocking_session_id
from blockingSessions
where blocking_session_id not in(select session_id from blockingSessions)
)--select * from causal
select t.text
,SPID = con.most_recent_session_id
,STATUS = s.STATUS
,[Login] = s.login_name
,Host = s.host_name
--,BlkBy = r.blocking_session_id
,DBName = d.name
,CommandType = r.command
,SQLStatement = t.text
,ObjectName = OBJECT_NAME(t.objectid)
,ElapsedMS = r.total_elapsed_time
,CPUTime = r.cpu_time
,IOReads = r.logical_reads + r.reads
,IOWrites = r.writes
,LastWaitType = r.last_wait_type
,StartTime = r.start_time
,Protocol = con.net_transport
,ConnectionWrites = con.num_writes
,ConnectionReads = con.num_reads
,ClientAddress = con.client_net_address
,Authentication = con.auth_scheme
--,t.*
from causal c
join sys.dm_exec_connections con
on c.blocking_session_id = con.session_id
join sys.dm_exec_sessions s
on con.most_recent_session_id = s.session_id
left join sys.dm_exec_requests r
on s.session_id = r.session_id
outer APPLY sys.dm_exec_sql_text(con.most_recent_sql_handle) AS t
left join sys.databases d
on t.dbid = d.database_id
但我一直无法弄清楚如何实现以下...
今天特定查询运行了多少次（不是自上次计划编译时间以来）？今天一个特定的存储过程今天运行了多少次？使用某些参数调用了多少次？
也许还有其他一些你们可以想到的有用的，也许你们可以为我上面给出的提供一些建议。我无法弄清楚的另一件事是动态管理视图中的连接、请求和会话之间的关系到底是什么？
编辑
我想我是专门尝试在特定时间段内使用视图，例如在 x 时间和 y 时间之间发生的情况。但它们似乎不是为此而设计的。这个对吗？是否有另一种方法可以从 sql server 按时间段获取类似信息？