SQL Server数据库配置改进

针对SQL Server数据库的配置，遵从最佳实践，有如下几项，看能否修改生产环境实例配置。

以下为调整方法和依据：

启动账号内存锁定

保证SQL Server提交内存不会被交换或空间被操作系统收缩。

The SQL Server 64-bit version uses "locked pages" to prevent the process working set (committed memory) from being paged out or trimmed by the operating system.

参考：

https://support.microsoft.com/en-us/kb/2659143

限制最大内存大小

保留一定内存供SQL Server连接内存、其它应用、系统内存等使用。

参考：

https://mssqlwiki.com/2013/04/22/max-server-memory-do-i-need-to-configure/

启动帐号即时文件初始化

快速初始化数据文件空间分配，减少等待。

This should be enabled in the vast majority of cases. SQL Server 2016 lets you enable this during the SQL server installation process.

参考：

Database Instant File Initialization

https://docs.microsoft.com/en-us/sql/relational-databases/databases/database-instant-file-initialization

Misconceptions around instant file initialization

https://www.sqlskills.com/blogs/paul/misconceptions-around-instant-file-initialization/

tempdb根据CPU核数配置多个文件

根据CPU核数配置多个相同配置的tempdb文件，提高tempdb的访问性能，已成为SQL Server 2016的标配。

参考：

https://www.derekseaman.com/2014/09/sql-2014-always-ag-pt-7-tempdb.html

https://blogs.msdn.microsoft.com/psssql/2016/03/17/sql-2016-it-just-runs-faster-automatic-tempdb-configuration/

https://blogs.sentryone.com/aaronbertrand/sql-server-2016-tempdb-fixes/

Trace Flag放到启动参数中

跟踪标志用于开启特定功能提高数据库性能。

Common trace flags that should be enabled in most cases

TF 1117 - When growing a data file, grow all files at the same time so they remain the same size, reducing allocation contention points

参考：

http://support2.microsoft.com/kb/2154845

TF 1118 - Helps alleviate allocation contention in tempdb, SQL Server allocates full extents to each database object, thereby eliminating the contention on SGAM pages (more important with older versions of SQL Server). Recommendations to reduce allocation contention in SQL Server tempdb database

参考：

http://support2.microsoft.com/kb/2154845

TF 2371 - Lowers auto update statistics threshold for large tables.

参考：

http://blogs.msdn.com/b/saponsqlserver/archive/2011/09/07/changes-to-automatic-update-statistics-in-sql-server-traceflag-2371.aspx

TF 3226 - Supresses logging of successful database backup messages to the SQL Server Error Log.

参考：

https://www.sqlskills.com/blogs/paul/fed-up-with-backup-success-messages-bloating-your-error-logs/

optimize for ad hoc workloads

优化即系查询的内存占用。

参考：

https://docs.microsoft.com/en-us/sql/database-engine/configure-windows/optimize-for-ad-hoc-workloads-server-configuration-option