sql性能分析语句

SET STATISTICS PROFILE ON --显示查询分析计划

SET STATISTICS TIME ON --显示查询时间
SET STATISTICS IO on --显示IO操作数


DBCC FREEPROCCACHE ---清楚计划缓存
DBCC DROPCLEANBUFFERS --清除数据缓存

SELECT creation_time N'语句编译时间'
,last_execution_time N'上次执行时间'
,total_physical_reads N'物理读取总次数'
,total_logical_reads/execution_count N'每次逻辑读次数'
,total_logical_reads N'逻辑读取总次数'
,total_logical_writes N'逻辑写入总次数'
, execution_count N'执行次数'
, total_worker_time/1000 N'所用的CPU总时间ms'
, total_elapsed_time/1000 N'总花费时间ms'
, (total_elapsed_time / execution_count)/1000 N'平均时间ms'
,SUBSTRING(st.text, (qs.statement_start_offset/2) + 1,
((CASE statement_end_offset
WHEN -1 THEN DATALENGTH(st.text)
ELSE qs.statement_end_offset END
- qs.statement_start_offset)/2) + 1) N'执行语句'
FROM sys.dm_exec_query_stats AS qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) st
where SUBSTRING(st.text, (qs.statement_start_offset/2) + 1,
((CASE statement_end_offset
WHEN -1 THEN DATALENGTH(st.text)
ELSE qs.statement_end_offset END
- qs.statement_start_offset)/2) + 1) not like '%fetch%'
ORDER BY creation_time desc;

-----查看所有索引
SELECT
TableId=O.[object_id],
TableName=O.Name,
IndexId=ISNULL(KC.[object_id],IDX.index_id),
IndexName=IDX.Name,
IndexType=ISNULL(KC.type_desc,'Index'),
Index_Column_id=IDXC.index_column_id,
ColumnID=C.Column_id,
ColumnName=C.Name,
Sort=CASE INDEXKEY_PROPERTY(IDXC.[object_id],IDXC.index_id,IDXC.index_column_id,'IsDescending')
WHEN 1 THEN 'DESC' WHEN 0 THEN 'ASC' ELSE '' END,
PrimaryKey=CASE WHEN IDX.is_primary_key=1 THEN N'√'ELSE N'' END,
[UQIQUE]=CASE WHEN IDX.is_unique=1 THEN N'√'ELSE N'' END,
Ignore_dup_key=CASE WHEN IDX.ignore_dup_key=1 THEN N'√'ELSE N'' END,
Disabled=CASE WHEN IDX.is_disabled=1 THEN N'√'ELSE N'' END,
Fill_factor=IDX.fill_factor,
Padded=CASE WHEN IDX.is_padded=1 THEN N'√'ELSE N'' END
FROM sys.indexes IDX
INNER JOIN sys.index_columns IDXC
ON IDX.[object_id]=IDXC.[object_id]
AND IDX.index_id=IDXC.index_id
LEFT JOIN sys.key_constraints KC
ON IDX.[object_id]=KC.[parent_object_id]
AND IDX.index_id=KC.unique_index_id
INNER JOIN sys.objects O
ON O.[object_id]=IDX.[object_id]
INNER JOIN sys.columns C
ON O.[object_id]=C.[object_id]
AND O.type='U'
AND O.is_ms_shipped=0
AND IDXC.Column_id=C.Column_id
where O.Name='uchome_message'
--    INNER JOIN  -- 对于一个列包含多个索引的情况,只显示第1个索引信息
--    (
--        SELECT [object_id], Column_id, index_id=MIN(index_id)
--        FROM sys.index_columns
--        GROUP BY [object_id], Column_id
--    ) IDXCUQ
--        ON IDXC.[object_id]=IDXCUQ.[object_id]
--            AND IDXC.Column_id=IDXCUQ.Column_id
{ LOOP | HASH | MERGE | REMOTE }

---------------------------------------------------------------------------------------------------------

1.服务器等待的原因查询
SELECT TOP 10
[Wait type] = wait_type,
[Wait time (s)] = wait_time_ms / 1000,
[% waiting] = CONVERT(DECIMAL(12,2), wait_time_ms * 100.0
               / SUM(wait_time_ms) OVER())
FROM sys.dm_os_wait_stats
WHERE wait_type NOT LIKE '%SLEEP%'
ORDER BY wait_time_ms DESC;
2.I/O 使用率较高可能表示数据访问机制不良。
SELECT TOP 10
        [Total Reads] = SUM(total_logical_reads)
        ,[Execution count] = SUM(qs.execution_count)
        ,DatabaseName = DB_NAME(qt.dbid)
FROM sys.dm_exec_query_stats qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) as qt
GROUP BY DB_NAME(qt.dbid)
ORDER BY [Total Reads] DESC;

SELECT TOP 10
        [Total Writes] = SUM(total_logical_writes)
        ,[Execution count] = SUM(qs.execution_count)
        ,DatabaseName = DB_NAME(qt.dbid)
FROM sys.dm_exec_query_stats qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) as qt
GROUP BY DB_NAME(qt.dbid)
ORDER BY [Total Writes] DESC;
3.检查高开销的已使用索引 -- Create required table structure only.
-- Note: this SQL must be the same as in the Database loop given in the following step.
SELECT TOP 1
        [Maintenance cost] = (user_updates + system_updates)
        ,[Retrieval usage] = (user_seeks + user_scans + user_lookups)
        ,DatabaseName = DB_NAME()
        ,TableName = OBJECT_NAME(s.[object_id])
        ,IndexName = i.name
INTO #TempMaintenanceCost
FROM   sys.dm_db_index_usage_stats s
INNER JOIN sys.indexes i ON s.[object_id] = i.[object_id]
    AND s.index_id = i.index_id
WHERE s.database_id = DB_ID()
    AND OBJECTPROPERTY(s.[object_id], 'IsMsShipped') = 0
    AND (user_updates + system_updates) > 0 -- Only report on active rows.
    AND s.[object_id] = -999 -- Dummy value to get table structure.
;

-- Loop around all the databases on the server.
EXEC sp_MSForEachDB    'USE [?];
-- Table already exists.
INSERT INTO #TempMaintenanceCost
SELECT TOP 10
        [Maintenance cost] = (user_updates + system_updates)
        ,[Retrieval usage] = (user_seeks + user_scans + user_lookups)
        ,DatabaseName = DB_NAME()
        ,TableName = OBJECT_NAME(s.[object_id])
        ,IndexName = i.name
FROM   sys.dm_db_index_usage_stats s
INNER JOIN sys.indexes i ON s.[object_id] = i.[object_id]
    AND s.index_id = i.index_id
WHERE s.database_id = DB_ID()
    AND i.name IS NOT NULL    -- Ignore HEAP indexes.
    AND OBJECTPROPERTY(s.[object_id], ''IsMsShipped'') = 0
    AND (user_updates + system_updates) > 0 -- Only report on active rows.
ORDER BY [Maintenance cost] DESC
;
'

-- Select records.
SELECT TOP 10 * FROM #TempMaintenanceCost
ORDER BY [Maintenance cost] DESC
-- Tidy up.
DROP TABLE #TempMaintenanceCost 4.逻辑上零碎的索引 -- Create required table structure only.
-- Note: this SQL must be the same as in the Database loop given in the -- following step.
SELECT TOP 1
        DatbaseName = DB_NAME()
        ,TableName = OBJECT_NAME(s.[object_id])
        ,IndexName = i.name
        ,[Fragmentation %] = ROUND(avg_fragmentation_in_percent,2)
INTO #TempFragmentation
FROM sys.dm_db_index_physical_stats(db_id(),null, null, null, null) s
INNER JOIN sys.indexes i ON s.[object_id] = i.[object_id]
    AND s.index_id = i.index_id
WHERE s.[object_id] = -999 -- Dummy value just to get table structure.
;

-- Loop around all the databases on the server.
EXEC sp_MSForEachDB    'USE [?];
-- Table already exists.
INSERT INTO #TempFragmentation
SELECT TOP 10
        DatbaseName = DB_NAME()
        ,TableName = OBJECT_NAME(s.[object_id])
        ,IndexName = i.name
        ,[Fragmentation %] = ROUND(avg_fragmentation_in_percent,2)
FROM sys.dm_db_index_physical_stats(db_id(),null, null, null, null) s
INNER JOIN sys.indexes i ON s.[object_id] = i.[object_id]
    AND s.index_id = i.index_id
WHERE s.database_id = DB_ID()
      AND i.name IS NOT NULL    -- Ignore HEAP indexes.
    AND OBJECTPROPERTY(s.[object_id], ''IsMsShipped'') = 0
ORDER BY [Fragmentation %] DESC
;
'

-- Select records.
SELECT TOP 10 * FROM #TempFragmentation ORDER BY [Fragmentation %] DESC
-- Tidy up.
DROP TABLE #TempFragmentation 5.高 I/O 开销的查询 SELECT TOP 10
[Average IO] = (total_logical_reads + total_logical_writes) / qs.execution_count
,[Total IO] = (total_logical_reads + total_logical_writes)
,[Execution count] = qs.execution_count
,[Individual Query] = 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)
        ,[Parent Query] = qt.text
,DatabaseName = DB_NAME(qt.dbid)
FROM sys.dm_exec_query_stats qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) as qt
ORDER BY [Average IO] DESC; 6.高 CPU 开销的查询SELECT TOP 10
[Average CPU used] = total_worker_time / qs.execution_count
,[Total CPU used] = total_worker_time
,[Execution count] = qs.execution_count
,[Individual Query] = 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)
,[Parent Query] = qt.text
,DatabaseName = DB_NAME(qt.dbid)
FROM sys.dm_exec_query_stats qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) as qt
ORDER BY [Average CPU used] DESC; 7.高开销的 CLR 查询 SELECT TOP 10
[Average CLR Time] = total_clr_time / execution_count
,[Total CLR Time] = total_clr_time
,[Execution count] = qs.execution_count
,[Individual Query] = 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)
,[Parent Query] = qt.text
,DatabaseName = DB_NAME(qt.dbid)
FROM sys.dm_exec_query_stats as qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) as qt
WHERE total_clr_time <> 0
ORDER BY [Average CLR Time] DESC; 8.最频繁的查询检测SELECT TOP 10[Execution count] = execution_count
,[Individual Query] = 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)
,[Parent Query] = qt.text
,DatabaseName = DB_NAME(qt.dbid)
FROM sys.dm_exec_query_stats qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) as qt
ORDER BY [Execution count] DESC; 9.最低计划重用率【存储过程】检测 SELECT TOP 10
[Plan usage] = cp.usecounts
,[Individual Query] = 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)
,[Parent Query] = qt.text
,DatabaseName = DB_NAME(qt.dbid)
,cp.cacheobjtype
FROM sys.dm_exec_query_stats qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) AS qt
INNER JOIN sys.dm_exec_cached_plans as cp on qs.plan_handle=cp.plan_handle
WHERE cp.plan_handle=qs.plan_handle
ORDER BY [Plan usage] ASC; 10. 受阻塞影响的查询检测 SELECT TOP 10
[Average Time Blocked] = (total_elapsed_time - total_worker_time) / qs.execution_count
,[Total Time Blocked] = total_elapsed_time - total_worker_time
,[Execution count] = qs.execution_count
,[Individual Query] = 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)
,[Parent Query] = qt.text
,DatabaseName = DB_NAME(qt.dbid)
FROM sys.dm_exec_query_stats qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) as qt
ORDER BY [Average Time Blocked] DESC;