2017年11月12日 星期日

WHERE 0 = (( CAST(CHARINDEX(N'Bill', [Extent1].[NAME]) AS int)) - 1)

            var result = from s1 in context.EMPLOYEE
                         where s1.NAME.IndexOf("Bill") == 0

=>上面的LINQ語法會產生以下SQL語法,滿少用到CHARINDEX
SELECT
    [Extent1].[ID] AS [ID],
    [Extent1].[NAME] AS [NAME]
    FROM [dbo].[EMPLOYEE] AS [Extent1]
    WHERE 0 = (( CAST(CHARINDEX(N'Bill', [Extent1].[NAME]) AS int)) - 1)

2017年11月6日 星期一

2017年11月1日 星期三

RAID 10、64 KB、SQL Server

Disk Performance Hands On, Part 2: RAID 10 Performance
http://www.kendalvandyke.com/2009/02/disk-performance-hands-on-part-2-raid.html
RAID 10 is the most commonly recommended type of configuration to house OLTP data files for SQL Server

SQL Server裝機磁區格式化需要使用64 KB的配置單位大小

https://www.sqlservercentral.com/Forums/Topic1804884-3411-1.aspx
SQL performs disk IO in extents and an extent is 8 pages, each of which are 8KB, for a total of 64KB

[SQL Server]改善I/O效能- NTFS Allocation Unit Size(4KB vs 64KB)
https://dotblogs.com.tw/stanley14/2016/09/18/063116

[SQL Server][裝機]:格式化資料磁碟,使用 64 KB 的 NTFS 配置單位大小(allocation unit size)
http://sharedderrick.blogspot.tw/2017/05/sql-server-64-kb-ntfs-allocation-unit.html

Understanding Pages and Extents
https://technet.microsoft.com/en-us/library/ms190969(v=sql.105).aspx

Disk Partition Alignment Best Practices for SQL Server
https://technet.microsoft.com/en-us/library/dd758814(v=sql.100).aspx

Introduction to Page and Extent in Sql Server
http://sqlhints.com/tag/pages-from-uniform-extent-in-sql-server-2016/