--获取有关按平均CPU 时间排在最前面的五个查询的信息
SELECT TOP 5 total_worker_time/execution_count AS [Avg CPU Time],
    SUBSTRING(st.text, (qs.statement_start_offset/2)+1,
        ((CASE qs.statement_end_offset
          WHEN -1 THEN DATALENGTH(st.text)
         ELSE qs.statement_end_offset
         END - qs.statement_start_offset)/2) + 1) AS statement_text
FROM sys.dm_exec_query_stats AS qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) AS st
ORDER BY total_worker_time/execution_count DESC;


--返回按批执行的SQL 查询的文本,并提供有关它们的统计信息。
--返回按批执行的SQL 查询的文本,并提供有关它们的统计信息。
SELECT top 20 s2.dbid,
    (SELECT TOP 1 SUBSTRING(s2.text,statement_start_offset / 2+1 ,
      ( (CASE WHEN statement_end_offset = -1
         THEN (LEN(CONVERT(nvarchar(max),s2.text)) * 2)
         ELSE statement_end_offset END)  - statement_start_offset) / 2+1))  AS sql_statement,
    execution_count,
    plan_generation_num,
    last_execution_time,  
    total_worker_time,
    last_worker_time,
    min_worker_time,
    max_worker_time,
    total_physical_reads,
    last_physical_reads,
    min_physical_reads, 
    max_physical_reads, 
    total_logical_writes,
    last_logical_writes,
    min_logical_writes,
    max_logical_writes 
FROM sys.dm_exec_query_stats AS s1
CROSS APPLY sys.dm_exec_sql_text(sql_handle) AS s2 
WHERE s2.objectid is null
ORDER BY  (total_worker_time/execution_count) desc,execution_count desc;


--为变更数据捕获日志扫描会话中遇到的每个错误返回一行
select * from sys.dm_cdc_errors


--返回AdventureWorks 数据库中Person.Address 表的所有索引和分区的信息。执行此查询至少需要对Person.Address 表具有CONTROL 权限
DECLARE @db_id smallint;
DECLARE @object_id int;
SET @db_id = DB_ID(N'AdventureWorks');
SET @object_id = OBJECT_ID(N'AdventureWorks.Person.Address');
IF @db_id IS NULL
  BEGIN;
    PRINT N'Invalid database';
  END;
ELSE IF @object_id IS NULL
  BEGIN;
    PRINT N'Invalid object';
  END;
ELSE
  BEGIN;
    SELECT * FROM sys.dm_db_index_operational_stats(@db_id, @object_id, NULL, NULL);
  END;
GO

--返回所有表和索引的信息
SELECT * FROM sys.dm_db_index_operational_stats(NULL, NULL, NULL, NULL);


--自动重新组织或重新生成数据库中平均碎片超过10%的所有分区
-- Ensure a USE <databasename> statement has been executed first.
SET NOCOUNT ON;
DECLARE @objectid int;
DECLARE @indexid int;
DECLARE @partitioncount bigint;
DECLARE @schemaname nvarchar(130);
DECLARE @objectname nvarchar(130);
DECLARE @indexname nvarchar(130);
DECLARE @partitionnum bigint;
DECLARE @partitions bigint;
DECLARE @frag float;
DECLARE @command nvarchar(4000);
-- Conditionally select tables and indexes from the sys.dm_db_index_physical_stats function
-- and convert object and index IDs to names.
SELECT
    object_id AS objectid,
    index_id AS indexid,
    partition_number AS partitionnum,
    avg_fragmentation_in_percent AS frag
INTO #work_to_do
FROM sys.dm_db_index_physical_stats (DB_ID(), NULL, NULL , NULL, 'LIMITED')
WHERE avg_fragmentation_in_percent > 10.0 AND index_id > 0;

-- Declare the cursor for the list of partitions to be processed.
DECLARE partitions CURSOR FOR SELECT * FROM #work_to_do;

-- Open the cursor.
OPEN partitions;

-- Loop through the partitions.
WHILE (1=1)
    BEGIN;
        FETCH NEXT
           FROM partitions
           INTO @objectid, @indexid, @partitionnum, @frag;
        IF @@FETCH_STATUS < 0 BREAK;
        SELECT @objectname = QUOTENAME(o.name), @schemaname = QUOTENAME(s.name)
        FROM sys.objects AS o
        JOIN sys.schemas as s ON s.schema_id = o.schema_id
        WHERE o.object_id = @objectid;
        SELECT @indexname = QUOTENAME(name)
        FROM sys.indexes
        WHERE  object_id = @objectid AND index_id = @indexid;
        SELECT @partitioncount = count (*)
        FROM sys.partitions
        WHERE object_id = @objectid AND index_id = @indexid;

-- 30 is an arbitrary decision point at which to switch between reorganizing and rebuilding.
        IF @frag < 30.0
            SET @command = N'ALTER INDEX ' + @indexname + N' ON ' + @schemaname + N'.' + @objectname + N' REORGANIZE';
        IF @frag >= 30.0
            SET @command = N'ALTER INDEX ' + @indexname + N' ON ' + @schemaname + N'.' + @objectname + N' REBUILD';
        IF @partitioncount > 1
            SET @command = @command + N' PARTITION=' + CAST(@partitionnum AS nvarchar(10));
        EXEC (@command);
        PRINT N'Executed: ' + @command;
    END;

-- Close and deallocate the cursor.
CLOSE partitions;
DEALLOCATE partitions;

-- Drop the temporary table.
DROP TABLE #work_to_do;
GO


--表及其索引的全部分区的所有计数
SELECT * FROM sys.dm_db_partition_stats
WHERE object_id = OBJECT_ID('dbo.dc_info_backup');

--返回有关在服务器上打开时间超过指定时间(小时)的游标的信息。
SELECT creation_time, cursor_id, name, c.session_id, login_name
FROM sys.dm_exec_cursors(0) AS c
JOIN sys.dm_exec_sessions AS s ON c.session_id = s.session_id
WHERE DATEDIFF(hh, c.creation_time, GETDATE()) > 36;

--查找连接到服务器的用户
SELECT login_name ,COUNT(session_id) AS session_count
FROM sys.dm_exec_sessions
GROUP BY login_name;

--查找长时间运行的游标
USE master;
GO
SELECT creation_time ,cursor_id
    ,name ,c.session_id ,login_name
FROM sys.dm_exec_cursors(0) AS c
JOIN sys.dm_exec_sessions AS s
   ON c.session_id = s.session_id
WHERE DATEDIFF(mi, c.creation_time, GETDATE()) > 5;


--查找具有已打开事务的空闲会话
SELECT s.*
FROM sys.dm_exec_sessions AS s
WHERE EXISTS
    (
    SELECT *
    FROM sys.dm_tran_session_transactions AS t
    WHERE t.session_id = s.session_id
    )
    AND NOT EXISTS
    (
    SELECT *
    FROM sys.dm_exec_requests AS r
    WHERE r.session_id = s.session_id
    );

--返回前五个查询的SQL 语句文本和平均CPU 时间。

SELECT TOP 5 total_worker_time/execution_count AS [Avg CPU Time],
    SUBSTRING(st.text, (qs.statement_start_offset/2)+1,
        ((CASE qs.statement_end_offset
          WHEN -1 THEN DATALENGTH(st.text)
         ELSE qs.statement_end_offset
         END - qs.statement_start_offset)/2) + 1) AS statement_text
FROM sys.dm_exec_query_stats AS qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) AS st
ORDER BY total_worker_time/execution_count DESC;

--返回按批执行的SQL 查询的文本,并提供有关它们的统计信息。
SELECT s2.dbid,
    s1.sql_handle, 
    (SELECT TOP 1 SUBSTRING(s2.text,statement_start_offset / 2+1 ,
      ( (CASE WHEN statement_end_offset = -1
         THEN (LEN(CONVERT(nvarchar(max),s2.text)) * 2)
         ELSE statement_end_offset END)  - statement_start_offset) / 2+1))  AS sql_statement,
    execution_count,
    plan_generation_num,
    last_execution_time,  
    total_worker_time,
    last_worker_time,
    min_worker_time,
    max_worker_time,
    total_physical_reads,
    last_physical_reads,
    min_physical_reads, 
    max_physical_reads, 
    total_logical_writes,
    last_logical_writes,
    min_logical_writes,
    max_logical_writes 
FROM sys.dm_exec_query_stats AS s1
CROSS APPLY sys.dm_exec_sql_text(sql_handle) AS s2 
WHERE s2.objectid is null
ORDER BY s1.sql_handle, s1.statement_start_offset, s1.statement_end_offset;

--返回每个数据库的缓存页计数

SELECT count(*)AS cached_pages_count
    ,CASE database_id
        WHEN 32767 THEN 'ResourceDb'
        ELSE db_name(database_id)
        END AS Database_name
FROM sys.dm_os_buffer_descriptors
GROUP BY db_name(database_id) ,database_id
ORDER BY cached_pages_count DESC;

--返回当前数据库中每个对象的缓存页计数

SELECT count(*)AS cached_pages_count
    ,name ,index_id
FROM sys.dm_os_buffer_descriptors AS bd
    INNER JOIN
    (
        SELECT object_name(object_id) AS name
            ,index_id ,allocation_unit_id
        FROM sys.allocation_units AS au
            INNER JOIN sys.partitions AS p
                ON au.container_id = p.hobt_id
                    AND (au.type = 1 OR au.type = 3)
        UNION ALL
        SELECT object_name(object_id) AS name  
            ,index_id, allocation_unit_id
        FROM sys.allocation_units AS au
            INNER JOIN sys.partitions AS p
                ON au.container_id = p.partition_id
                    AND au.type = 2
    ) AS obj
        ON bd.allocation_unit_id = obj.allocation_unit_id
WHERE database_id = db_id()
GROUP BY name, index_id
ORDER BY cached_pages_count DESC;

--确定群集服务器实例上的节点
SELECT * FROM sys.dm_os_cluster_nodes

--sql 性能计数
Select * from sys.dm_os_performance_counters

--获取某个数据库表的字段数、记录数、占用空间和索引空间大小
set nocount on
exec sp_MSForEachTable
@precommand=N'
create table ##(
id int identity,
表名sysname,
字段数int,
记录数int,
保留空间Nvarchar(10),
使用空间varchar(10),
索引使用空间varchar(10),
未用空间varchar(10))',
@command1=N'insert ##(表名,记录数,保留空间,使用空间,索引使用空间,未用空间) exec sp_spaceused ''?''
        update ## set 字段数=(select count(*) from syscolumns where id=object_id(''?'')) where id=scope_identity()',
@postcommand=N'select * from ## order by 记录数desc drop table ##'
set nocount off

--获取数据表的信息
ALTER proc [dbo].[usp_dc_info_tableinfo]
as
declare @a nvarchar(50),@b nvarchar(max)
declare cur cursor for select name from sys.databases where database_id>=5 and database_id not in (23)
open cur
fetch cur into @a
while (@@fetch_status=0)
begin
set @b='
use '+@a+'
declare @s varchar(1000)
 
  begin
  create   table   #ip(id   int   identity(1,1),re   varchar(200))  
  set @s=''ping   ''+left(@@servername,charindex(''\'',@@servername+''\'')-1)+''   -a   -n   1   -l   1''  
  insert   #ip(re)   exec   master..xp_cmdshell   @s 

  create table #statistic (Tablename nvarchar(50),rows int,reserved nvarchar(50),data nvarchar(50),index_size nvarchar(50),unused nvarchar(50),InsertDate datetime default getdate())
 
  Insert into #statistic(Tablename,rows,reserved,data,index_size,unused) execute sp_msforeachtable ''sp_spaceused''''?''''''
 
  Insert into DBcenter..dc_info_tableinfo
  Select *
    from
     (select IP=stuff(left(re,charindex('']'',re)-1),1,charindex(''['',re),''''),DatabaseName=db_name() 
       from   #ip  
         where id=2   ) a
     cross join
     #statistic b
 end

drop table #statistic
drop table #ip
'
execute (@b)
print @b
fetch cur into @a
end
close cur
deallocate cur

--显示锁信息
SELECT resource_type, resource_associated_entity_id,
    request_status, request_mode,request_session_id,
    resource_description
    FROM sys.dm_tran_locks
    --WHERE resource_database_id = 6

--显示阻塞信息
SELECT
        t1.resource_type,
        t1.resource_database_id,
        t1.resource_associated_entity_id,
        t1.request_mode,
        t1.request_session_id,
        t2.blocking_session_id
    FROM sys.dm_tran_locks as t1
    INNER JOIN sys.dm_os_waiting_tasks as t2
        ON t1.lock_owner_address = t2.resource_address;

--显示磁盘可用空间
EXEC master..xp_fixeddrives