CREATE DATABASE test_shrinkUSE test_shrinkCREATE TABLE show_extent(a INT,b NVARCHAR(3900))DECLARE @i INT
SET @i=1
WHILE @i<=100BEGININSERT INTO show_extent VALUES(1,REPLICATE(N'a',3900))INSERT INTO show_extent VALUES(2,REPLICATE(N'b',3900))INSERT INTO show_extent VALUES(3,REPLICATE(N'c',3900))INSERT INTO show_extent VALUES(4,REPLICATE(N'd',3900))INSERT INTO show_extent VALUES(5,REPLICATE(N'e',3900))INSERT INTO show_extent VALUES(6,REPLICATE(N'f',3900))INSERT INTO show_extent VALUES(7,REPLICATE(N'g',3900))INSERT INTO show_extent VALUES(8,REPLICATE(N'h',3900))SET @i=@i+1END--检查索引碎片DBCC SHOWCONTIG('show_extent')--删除a列不是5的数据DELETE dbo.show_extent WHERE a<>5--显示数据文件  64kbEXEC sys.sp_spaceused @objname = N'show_extent' -- nvarchar(776)DBCC SHOWCONTIG('show_extent')--查看数据库的文件和日志大小EXEC sys.sp_helpfile--fileid为1 收缩到40MBDBCC SHRINKFILE(2,40)--建立索引释放没有使用的区CREATE CLUSTERED INDEX show_I ON dbo.show_extent(a)--检查索引碎片DBCC SHOWCONTIG('show_extent')--收缩文件DBCC SHRINKFILE(1,1)--查看数据库的占用空间和未分配的空间EXEC sys.sp_spaceused @objname = N'show_extent'SELECT * FROM dbo.show_extent--找出每个区的对象理论上区数目和实际数目,然后重建大对象类型的表USE test_shrink--建立临时表CREATE TABLE #extentinfo([file_id] SMALLINT,page_id INT,pg_alloc INT,ext_size INT,obj_id INT,index_id INT,partition_number INT,partition_id BIGINT,iam_chain_type VARCHAR(50),pfs_bytes VARBINARY(10))CREATE PROCEDURE import_extentinfoasDBCC extentinfoDBCC extentinfo('test_shrink')INSERT INTO #extentinfo EXEC import_extentinfoSELECT [file_id],obj_id,index_id,partition_id,ext_size,'actual extent count'=COUNT(*),'actual page count'=SUM(pg_alloc),'possible extent count'=ceiling(SUM(pg_alloc)*1.0/ext_size),'possible extents/actual extents'=(ceiling(SUM(pg_alloc)*1.00/ext_size)*100.00)/COUNT(*)
FROM #extentinfoGROUP BY file_id,obj_id,index_id,partition_id,ext_sizeHAVING COUNT(*) -ceiling(SUM(pg_alloc)*1.0/ext_size)>0ORDER BY partition_id,obj_id,index_id,file_id--SQL2005以后有一个动态管理视图sys.dm_exec_query_stats,返回缓存查询计划的性能统计信息--SQL会统计从上次SQL启动以来，一共做了多少次logical读写，多少次physical读，还记录执行所用的   CPU时间总量--按照物理读的页面数排序 前50名SELECT TOP 50qs.total_physical_reads,qs.execution_count,qs.total_physical_reads/qs.execution_count AS [avg I/O],--截取字符串SUBSTRING(qt.text,qs.statement_start_offset/2,(CASE WHEN qs.statement_end_offset=-1THEN LEN(CONVERT(NVARCHAR(max),qt.text))*2ELSE qs.statement_end_offset END -qs.statement_start_offset)/2) AS query_text,qt.dbid,dbname=DB_NAME(qt.dbid),qt.objectid,qs.sql_handle,qs.plan_handlefrom sys.dm_exec_query_stats qsCROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) AS qtORDER BY qs.total_physical_reads DESC--SQL Trace里面有一个reads字段，记录了某条语句完成过程中一共做了多少次读的动作，找到read最多的语句--每个SQL Trace里有成千成万的语句，可以使用fn_trace_gettable 像一张表一样把trace文件里的记录查询出来--可以用他将记录转入到SQLSERVER里，然后用查询语句进行统计分析。SELECT * INTO #SAMPLEFROM sys.fn_trace_gettable('C:\Users\Administrator\Desktop\1.trc',DEFAULT)WHERE EventClass IN(10,12)select * from sys.sysprocesses--运行下面DBCC命令释放SQL内存缓存DBCC freesessioncacheDBCC freeproccache

  SELECT TOP 50qs.total_physical_reads,qs.execution_count,qs.total_physical_reads/qs.execution_count AS [avg I/O],--截取字符串SUBSTRING(qt.text,qs.statement_start_offset/2,(CASE WHEN qs.statement_end_offset=-1THEN LEN(CONVERT(NVARCHAR(max),qt.text))*2ELSE qs.statement_end_offset END -qs.statement_start_offset)/2) AS query_text,qt.dbid,dbname=DB_NAME(qt.dbid),qt.objectid,qs.sql_handle,qs.plan_handlefrom sys.dm_exec_query_stats qsCROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) AS qtORDER BY qs.total_physical_reads DESC

 --检查语句：SELECT CONVERT(VARCHAR(30),GETDATE(),121) AS runtime,resource_semaphore_id,target_memory_kb,total_memory_kb,available_memory_kb,granted_memory_kb,used_memory_kb,grantee_count,waiter_count,timeout_error_countfrom sys.dm_exec_query_resource_semaphores

SELECT GETDATE() AS runtime,session_id,scheduler_id,dop,request_time,grant_time,requested_memory_kb,granted_memory_kb,used_memory_kb,timeout_sec,query_cost,resource_semaphore_id,wait_order,is_next_candidate,wait_time_ms,REPLACE(REPLACE(CAST(s2.text AS VARCHAR(4000)),CHAR(10),''),CHAR(13),'') AS sql_statementFROM sys.dm_exec_query_memory_grants
CROSS APPLY sys.dm_exec_sql_text(sql_handle) AS s2

 SELECThighest_cpu_queries.*,highest_cpu_queries.total_worker_time,DB_NAME(q.dbid)  AS dbname,q.[text] AS qtextfrom(SELECT TOP 50 qs.* from sys.dm_exec_query_stats qs ORDER BY qs.total_worker_time DESC) AS highest_cpu_queriesCROSS APPLY sys.dm_exec_sql_text(plan_handle) AS q
ORDER BY highest_cpu_queries.total_worker_time DESC

 SELECT TOP 25sql_text.text AS sqltext,sql_handle AS sqlhandle,plan_generation_num AS plangenerationnum,execution_count AS execcount,DB_NAME(dbid) AS dbname,objectid AS objectidfrom sys.dm_exec_query_stats aCROSS APPLY sys.dm_exec_sql_text(sql_handle) AS sql_textWHERE plan_generation_num>1ORDER BY plan_generation_num DESC

 --返回最经常运行的100条语句SELECT TOP 100cp.cacheobjtype,cp.usecounts,cp.size_in_bytes,qs.statement_start_offset,qs.statement_end_offset,qt.dbid,qt.objectid,SUBSTRING(qt.text,qs.statement_start_offset/2,CASE WHEN qs.statement_end_offset=-1 THEN LEN(CONVERT(NVARCHAR(max),qt.text))*2 ELSE qs.statement_end_offset END -qs.statement_start_offset/2)AS statementfrom sys.dm_exec_query_stats qsCROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) AS qtINNER JOIN sys.dm_exec_cached_plans AS cp ON qs.plan_handle=cp.plan_handleWHERE cp.plan_handle=qs.plan_handleAND cp.usecounts>4ORDER BY dbid,usecounts DESC