随笔分类 -  sql performance tuning

摘要：Improve Indexes Creating useful indexes is one of the most important ways to achieve better query performance. Useful indexes help you find data with fewer disk I/O operations and less system resource... 阅读全文

摘要：with waits as ( select wait_type, wait_time_ms / 1000 as wait_time_s, 100. * wait_time_ms / SUM(wait_time_ms) over() as pct, ROW_NUMBER() over(order by wait_time_ms desc) as rn from sys.dm_os_wa... 阅读全文