祥解磁盘 IO 性能 对数据库的影响（国外英文资料）.docVIP

祥解磁盘 IO 性能 对数据库的影响（国外英文资料） The impact of the disk I/O performance on the database If the SQL Server is configured to contain only a few gigabytes (GB), and does not bear the heavy to read or write, there isnt much need to pay attention to disk I/O the theme, and to balance between hard disk SQL Server I/O activities in order to get the best performance. But to build a contains hundreds of GB byte of data and/or bear heavy reading and/or writing activities of large SQL Server database, it is necessary to balance the load between multiple hard, best to configure the SQL Server disk I/O performance. Nominal disk transmission rate is associated with SQL Server One of the most important aspects of optimizing database performance is tuning I/O performance. SQL Server is no exception, of course. Unless the SQL Server running on a has enough memory capacity of the entire database machine, otherwise I/O performance will be handled by disk I/O subsystem to SQL Server data read and write speed. Please remember the following rules of thumb: standard of Wide Ultra SCSI - 3 hard disk every second to provide Windows and SQL Server 75 discrete random I/O operations and 150 serial I/O operations. The hard drives nominal transmission rate is about 40 megabits per second. Keep in mind that it is more likely that the database server will be limited to 75/150 I/O per second, rather than 40 megabytes per second. The details are as follows: (75 random I/O operations per second) X (8 KB) = 600 KB per second If the calculated said in a given disk to carry on the strict random read or write SQL Server (single page to read and write) operation, likely the hard disk can only up to 600 KB per second (0.6 MB) per second of processing capacity. This is much lower than the 40-megabyte I/O processing capacity of the drive. The SQL Server worker thread, the data ShowPlan, and LazyWrtier execute the I/O for 8 KB transfers. (150 consecutive I/O operations per second) X (8 KB) = 1, 200 KB per second Th