今天發生一個SQL奇怪的現象，記錄一下
就是訂單列表(使用分頁的SQL 找出 top 20)跑很久才出來，大約10多秒 
SQL指令條件僅有訂單日期(預設是1年內訂單，訂單總數有130萬筆)，而訂單日期也有做index
之前都大約1~2秒就出來，這一兩天卻要10秒才跑出來

用執行計畫評估功能查也看不出哪裡有問題，把一些子查詢拿掉也沒有改善
所以就改一下搜尋條件，改搜尋半年內訂單，大約 5秒
改搜尋兩年內訂單，1秒!!! 真是神奇，把條件區間拉大反而很快???????
直覺上覺得索引table是不是太大太亂了，剛好看到CreateDate索引有個重建按鈕
就勇敢把他按下去，想說會不會跑很久，結果重建只要不到1秒就好了
然後神奇的事發生了，訂單列表不須一秒就顯示出來啦!

SQL 指令大概長這樣

Select * from (

Select Top 20 * from (

select Top 20 a.*

--, CompelteOrderId= (select top 1 K.Id from packing_list_main k With(NoLock) join Order_Main p With(NoLock) on k.Order_Id=p.Id where k.En_Packing_List_Status=300 and P.MEmber_Id=a.Member_Id )

--, [MemoCount_前台問題] = (Select COUNT(*) from Order_Memo With(NoLock) where Order_Memo.Order_Id = a.Id and Memo_Type = 1)

--, [MemoCount_業務備註] = (Select COUNT(*) from Order_Memo With(NoLock) where Order_Memo.Order_Id = a.Id and Memo_Type = 3)

--, [MemoCount_系統檢查] = (Select COUNT(*) from Order_Memo With(NoLock) where Order_Memo.Order_Id = a.Id and Memo_Type = 4)

--, QnACount = (select count(*) from Order_QnA With(NoLock) where Order_Id = a.Id)

from V_Order_Main_For_Admin_List a With(NoLock) left join Member b with(NoLock) on a.Member_Id=b.Id where (1=1) and En_Order_Status <> -300 and a.Create_Date >='2018-06-20' order by Id Desc

) AS T1 order by Id

) AS T2 order by Id Desc

參考 will will web 的舊文章，原來定期把索引整理整理，也是要記得做的。
不過週期上我想 1季或半年跑一次應該就可以了
-------------------------------------------------------------------
後記: 2020/6/22 -  一年後又發生一樣的狀況，真是神奇
這次 OrderMain CreateDate 沒有很分散。只有 2.X %
想說其他 index 是不是該重建，但是都沒有效果
最後只好重建 CreateDate --> 結果居然解決了

看 2021年會在發生嗎?

 

如下, 要記得修改 database_name, userOLD, userNEW 三個參數

CREATE TABLE #Command

    (

    Id int NOT NULL IDENTITY (1, 1),

    command nvarchar(MAX) NOT NULL

    )  ON [PRIMARY]

     TEXTIMAGE_ON [PRIMARY]

GO



USE database_name  -- Use the database from which you want to extract the permissions

GO



SET NOCOUNT ON



DECLARE @OldUser sysname, @NewUser sysname



SET @OldUser = 'userOLD' --The user or role from which to copy the permissions from

SET @NewUser = 'userNEW' --The user or role to which to copy the permissions to



insert into #Command(command)

Select convert(nvarchar(max), '--Database Context')



insert into #Command(command)

SELECT 'USE' + SPACE(1) + QUOTENAME(DB_NAME())



insert into #Command(command)

SELECT '--Cloning permissions from' + SPACE(1) + QUOTENAME(@OldUser) + SPACE(1) + 'to' + SPACE(1) + QUOTENAME(@NewUser)



insert into #Command(command)

SELECT 'EXEC sp_addrolemember @rolename ='

    + SPACE(1) + QUOTENAME(USER_NAME(rm.role_principal_id), '''') + ', @membername =' + SPACE(1) + QUOTENAME(@NewUser, '''') AS '--Role Memberships'

FROM    sys.database_role_members AS rm

WHERE USER_NAME(rm.member_principal_id) = @OldUser

ORDER BY rm.role_principal_id ASC



insert into #Command(command)

SELECT CASE WHEN perm.state <> 'W' THEN perm.state_desc ELSE 'GRANT' END

    + SPACE(1) + perm.permission_name + SPACE(1) + 'ON ' + QUOTENAME(USER_NAME(obj.schema_id)) + '.' + QUOTENAME(obj.name)

    + CASE WHEN cl.column_id IS NULL THEN SPACE(0) ELSE '(' + QUOTENAME(cl.name) + ')' END

    + SPACE(1) + 'TO' + SPACE(1) + QUOTENAME(@NewUser) COLLATE database_default

    + CASE WHEN perm.state <> 'W' THEN SPACE(0) ELSE SPACE(1) + 'WITH GRANT OPTION' END AS '--Object Level Permissions'

FROM    sys.database_permissions AS perm

    INNER JOIN

    sys.objects AS obj

    ON perm.major_id = obj.[object_id]

    INNER JOIN

    sys.database_principals AS usr

    ON perm.grantee_principal_id = usr.principal_id

    LEFT JOIN

    sys.columns AS cl

    ON cl.column_id = perm.minor_id AND cl.[object_id] = perm.major_id

WHERE usr.name = @OldUser

ORDER BY perm.permission_name ASC, perm.state_desc ASC



insert into #Command(command)

SELECT CASE WHEN perm.state <> 'W' THEN perm.state_desc ELSE 'GRANT' END

    + SPACE(1) + perm.permission_name + SPACE(1)

    + SPACE(1) + 'TO' + SPACE(1) + QUOTENAME(@NewUser) COLLATE database_default

    + CASE WHEN perm.state <> 'W' THEN SPACE(0) ELSE SPACE(1) + 'WITH GRANT OPTION' END AS '--Database Level Permissions'

FROM    sys.database_permissions AS perm

    INNER JOIN

    sys.database_principals AS usr

    ON perm.grantee_principal_id = usr.principal_id

WHERE usr.name = @OldUser

AND perm.major_id = 0

ORDER BY perm.permission_name ASC, perm.state_desc ASC



Select command from #Command order by Id

drop table #Command

SELECT e.name, e.protocol_desc, e.type_desc, e.role_desc, e.state_desc, 
       t.port, e.is_encryption_enabled, e.encryption_algorithm_desc, 
       e.connection_auth_desc 
FROM   sys.database_mirroring_endpoints e JOIN sys.tcp_endpoints t
ON     e.endpoint_id = t.endpoint_id;


--這個步驟要看前一步驟出現的 Name , 修改 'DBMirroringEndPoint'
IF  EXISTS (SELECT * FROM sys.endpoints e WHERE e.name = N'DBMirroringEndPoint')
DROP ENDPOINT  DBMirroringEndPoint; 

IF NOT EXISTS (SELECT * FROM sys.endpoints e WHERE e.name = N'DBMirroringEndPoint') 
CREATE ENDPOINT DBMirroringEndPoint
    STATE = STARTED
    AS TCP ( LISTENER_PORT = 5023 )
    FOR DATABASE_MIRRORING (
       AUTHENTICATION = WINDOWS NEGOTIATE,
       ENCRYPTION = REQUIRED,
       ROLE=ALL);

修改完畢, 在做 Security 設定時會看到新的 port "5023"

 

<範例>
Table: [員工資料表]
欄位: [主管], [員工]

需求是: 當輸入一個員工姓名, 要把該員工下面所有階層的員工都Show出來

SQL語法:
 

WITH [員工資料表new] AS (

--找出 [主管] 為 某人的資料當作 依據

SELECT [主管], [員工]

FROM [員工資料表]

WHERE [主管] = 'XXXX'



UNION ALL



--之後以 上面查出的結果 為依據遞迴查詢

SELECT e.[主管], e.[員工]

FROM [員工資料表] e

INNER JOIN [員工資料表new] ecte ON ecte.[員工] = e.[主管]

)

SELECT *

FROM [員工資料表new]

參考網站: [SQL] 遞迴的寫法

--抓所有的 Table
Select * from INFORMATION_SCHEMA.TABLES

--抓所有的 COLUMNS
Select * from INFORMATION_SCHEMA.COLUMNS


--抓欄位的 Description
select 
    st.name [Table],
    sc.name [Column],
    sep.value [Description]
from sys.tables st
inner join sys.columns sc on st.object_id = sc.object_id
left join sys.extended_properties sep on st.object_id = sep.major_id
                                        and sc.column_id = sep.minor_id
                                        and sep.name = 'MS_Description'
where st.name = 'TableName'
and sc.name = 'ColumnName'

--修改欄位的 Description.
EXEC sp_updateextendedproperty 
@name = N'MS_Description', @value = 'Your description',
@level0type = N'Schema', @level0name = 'dbo', 
@level1type = N'Table',  @level1name = 'TableName', 
@level2type = N'Column', @level2name = 'Name';


EXEC sp_addextendedproperty 
@name = N'MS_Description', @value = 'Code description',
@level0type = N'Schema', @level0name = 'dbo', 
@level1type = N'Table',  @level1name = 'TableName', 
@level2type = N'Column', @level2name = 'ColumnName';



--新增 Table 的 extendedproperty
EXEC sp_addextendedproperty 
@name = N'Description', @value = 'Hey, here is TableName description!',
@level0type = N'Schema', @level0name = 'dbo',
@level1type = N'Table',  @level1name = 'TableName'
GO

--修改 Table 的 extendedproperty
EXEC sp_updateextendedproperty 
@name = N'Description', @value = 'Hey, here is my description! 123',
@level0type = N'Schema', @level0name = 'dbo',
@level1type = N'Table',  @level1name = 'TableName'
GO


--讀取 Extended Property
SELECT sys.objects.name AS TableName, ep.name AS PropertyName,
       ep.value AS Description
FROM sys.objects
CROSS APPLY fn_listextendedproperty(default,
                                    'SCHEMA', schema_name(schema_id),
                                    'TABLE', name, null, null) ep
WHERE sys.objects.name NOT IN ('sysdiagrams')
ORDER BY sys.objects.name

--讀取 Column 的 Description
SELECT objtype, objname, name, value  
FROM fn_listextendedproperty (NULL, 'schema', 'dbo', 'table', 'TableName', 'column', default);  
GO

--讀取特定 Table 的 Description
SELECT *  
FROM fn_listextendedproperty (NULL, 'schema', 'dbo', 'table', 'TableName', default, default);  
GO  

--讀取 所有 Table 的 Description
SELECT *  
FROM fn_listextendedproperty (NULL, 'schema', 'dbo', 'table', default, default, default);  
GO  


--新增或修改資料表說明
IF not exists(SELECT * FROM ::fn_listextendedproperty (NULL, 'user', 'dbo', 'table', '資料表名稱', NULL, NULL))  
           BEGIN  
            exec sp_addextendedproperty 'MS_Description', '資料表說明', 'user', 'dbo', 'table', '資料表名稱' 
           END  
ELSE 
           BEGIN  
            exec sp_updateextendedproperty 'MS_Description', '資料表說明', 'user', 'dbo', 'table', '資料表名稱' 
           END

--新增或修改欄位說明
IF not exists(SELECT * FROM ::fn_listextendedproperty (NULL, 'user', 'dbo', 'table', '資料表名稱', 'column', '欄位名稱')) 
           BEGIN  
            exec sp_addextendedproperty 'MS_Description', '欄位說明', 'user', 'dbo', 'table', '資料表名稱', 'column', '欄位名稱' 
           END  
ELSE 
           BEGIN  
            exec sp_updateextendedproperty 'MS_Description', '欄位說明', 'user', 'dbo', 'table', '資料表名稱', 'column', '欄位名稱' 
           END

取得CheckBoxList多選值的方式：

【未使用Linq的寫法】

       Dim values = New List(Of String)()
       For Each item As ListItem In Me.CheckBoxList1.Items
             If item.Selected Then
                  values.Add(item.Value)
             End If
       Next

       Dim result = String.Join(",", values.ToArray(Of String)())
 

【使用Linq的寫法】

               Dim result = String.Join(",", Me.CheckBoxList1.Items.Cast(Of ListItem)() _
                                   .Where(Function(x) x.Selected) _
                                   .[Select](Function(x) x.Value).ToArray())

p.s. Linq需使用.NET Framework 3.5以上的版本

半夜被老闆 Line，跟我說網頁發生錯誤，他無法看統計報表，會出現作業逾時的錯誤 我查了一下網頁程式，發現是這筆SQL指令跑太久

 Select Id, (IsNull(Total, 0) - IsNull(CouponDiscount, 0) + IsNull(CouponAdd, 0)) as Total, Buyer_Email, EN_Packing_List_Status, EN_Order_Source, En_Stock_Status, Create_Date

From V_Order_main With(Nolock)

Where Id in (select Order_Id from Ad_Trace With(NoLock) where (Parameter_Id = 14278))

AND Create_Date >= '2014/10/3' And Create_Date < '2014/10/12' 

--> 跑了50秒~ 1分鐘

 Select Id, (IsNull(Total, 0) - IsNull(CouponDiscount, 0) + IsNull(CouponAdd, 0)) as Total, Buyer_Email, EN_Packing_List_Status, EN_Order_Source, En_Stock_Status, Create_Date

From V_Order_main With(Nolock)

Where Id in (select Order_Id from Ad_Trace With(NoLock) where (Parameter_Id = 14278))

--> 拿掉日期限制 > 秒殺，  結果跑出 47 筆資料

跑一下執行計畫 原來子查詢的 Ad_Trace 沒有建立Index造成


加上 Index 之後，再跑第一支SQL --> 秒殺

奇怪的地方:
明明訂單日期欄位(Create_Date) 跟 Ad_Trace 沒有多大關係，但是加上日期限制之後，居然會引發 Ad_Trace 搜尋過久的現象
他好像是先依照訂單日期找出所有訂單，然後再從子查詢 Ad_Trace 裡面搜尋有無符合的條件訂單
而不是先跑子查詢找出 Ad_Trace 所有的 Order_Id，再去找符合 Create_Date 的訂單

SQL內部運作的機制真是有點讓人想不透，幸好有評估計畫可以看出問題在哪裡
這讓我想起以前學SQL時的一句話 => 盡量用Join來取代子查詢
使用子查詢真的是效能殺手啊

------繼續補充--------------------------------------

上面的SQL在雙11活動後，由於當日訂單過多，一樣造成SQL timeout 的現象，研判還是子查詢造成的問題

Select Id, (IsNull(Total, 0) - IsNull(CouponDiscount, 0) + IsNull(CouponAdd, 0)) as Total, Buyer_Email, EN_Packing_List_Status, EN_Order_Source, En_Stock_Status, Create_Date

From V_Order_main With(Nolock)

Where Id in (select Order_Id from Ad_Trace With(NoLock) where (Parameter_Id = 14720))

And Create_Date > '2014-11-10' And Create_Date < '2014-11-11'

--> 跑了51秒

所以先將子查詢拿出來跑出一串字串 865828,865890,865901,865903,865928,865955,865990,865993,866005,866035.....
(共1452筆)
再把他拼入sql跑   --> 7秒
 

當進行玩物件Update指令之後～不見得所有的資訊會跟著更新～
舉例：
ShippingInfo 在Update之後
ShippingInfo.FullAddress的內容為
Me.Post_Code & Me.County_Name & Me.City_Name & Me.Address

但是Me.County_Name & Me.City_Name的部分是用join出來的～
所以不會更新
因此地址部分會是錯誤的～

所以在執行update完之後～還是重新再new一次以保資料會是最新的～

USE [master]

GO

/****** Object: StoredProcedure [dbo].[sp_who3]    Script Date: 06/26/2008 09:40:54 ******/

SET ANSI_NULLS ON

GO

SET QUOTED_IDENTIFIER ON

GO

CREATE PROCEDURE [dbo].[sp_who3]    

(    

@filter tinyint = 1,    

@filterspid int = NULL    

)    

AS    

SET NOCOUNT ON;    

    

DECLARE @processes TABLE    

(    

spid int,    

blocked int,    

databasename varchar(256),    

hostname varchar(256),    

program_name varchar(256),    

loginame varchar(256),    

status varchar(60),    

cmd varchar(128),    

cpu int,    

physical_io int,    

[memusage] int,    

login_time datetime,    

last_batch datetime,    

current_statement_parent xml,

current_statement_sub xml)



INSERT INTO @processes    

SELECT sub.*

FROM

(

SELECT sp.spid,    

sp.blocked,    

sd.name,    

RTRIM(sp.hostname) AS hostname,

RTRIM(sp.[program_name]) AS [program_name],    

RTRIM(sp.loginame) AS loginame,    

RTRIM(sp.status) AS status,    

sp.cmd,    

sp.cpu,    

sp.physical_io,    

sp.memusage,    

sp.login_time,    

sp.last_batch,

(

    SELECT

LTRIM(st.text) AS [text()]

    FOR XML PATH(''), TYPE

) AS parent_text,

(

    SELECT

LTRIM(CASE

WHEN LEN(COALESCE(st.text, '')) = 0 THEN NULL

ELSE SUBSTRING(st.text, (er.statement_start_offset/2)+1,

((CASE er.statement_end_offset

WHEN -1 THEN DATALENGTH(st.text)

ELSE er.statement_end_offset

END - er.statement_start_offset)/2) + 1)

END) AS [text()]

FROM sys.dm_exec_requests er CROSS APPLY sys.dm_exec_sql_text(er.sql_handle) AS st

WHERE er.session_id = sp.spid

    FOR XML PATH(''), TYPE

) AS child_text

FROM sys.sysprocesses sp WITH (NOLOCK) LEFT JOIN sys.sysdatabases sd WITH (NOLOCK) ON sp.dbid = sd.dbid

CROSS APPLY sys.dm_exec_sql_text(sp.sql_handle) AS st

) sub INNER JOIN sys.sysprocesses sp2 ON sub.spid = sp2.spid

ORDER BY

sub.spid



-- if specific spid required    

IF @filterspid IS NOT NULL    

DELETE @processes    

WHERE spid <> @filterspid    

    

-- remove system processes    

IF @filter = 1 OR @filter = 2    

DELETE @processes    

WHERE spid < 51

OR spid = @@SPID

    

-- remove inactive processes    

IF @filter = 2    

DELETE @processes    

WHERE status = 'sleeping'    

AND cmd IN ('AWAITING COMMAND')    

AND blocked = 0    



SELECT spid,    

blocked,    

databasename,    

hostname,    

loginame,    

status,    

current_statement_parent,

current_statement_sub,

cmd,    

cpu,    

physical_io,    

program_name,    

login_time,    

last_batch    

FROM @processes    

ORDER BY spid



RETURN 0; 

查詢過濾sp_who3

DECLARE @Table TABLE(

        spid int,    

        blocked int,    

        databasename varchar(256),    

        hostname varchar(256),    

        loginame varchar(256),    

        status varchar(60),    

        current_statement_parent xml,

        current_statement_sub xml,

        cmd varchar(128),    

        cpu int,    

        physical_io int,    

        program_name varchar(256),    

        login_time datetime,    

        last_batch datetime

)



INSERT INTO @Table EXEC sp_who3



SELECT *

FROM    @Table

WHERE databasename= 'Leon' and cmd = 'AWAITING COMMAND'

and CAST(current_statement_parent AS nvarchar(max)) not LIKE '%AspNet_SqlCachePollingStoredProcedure%'

order by CAST(current_statement_parent AS nvarchar(max))

使用 Left Join 似乎可以減少 DB  的 Loading, 有空再來試一下。