如何新建索引:高开销的缺失索引

索引对查询性能影响极大，不要盲目的新建索引！数据库高开销的缺失索引 ,根据对动态性能视图的统计信息，新建需要的索引！

select c.name as 库名,c.equality_columns,

c.inequality_columns,c.included_columns,

c.statement as 表名,

c.avg_total_user_cost as 减少的平均成本 ,

c.avg_user_impact as 百分比收益,

c.last_user_seek as 使用后影响上次结果,

c.unique_compiles

from

(

select a.name,b.* from

(

select d.*

, s.avg_total_user_cost

, s.avg_user_impact

, s.last_user_seek

,s.unique_compiles

from sys.dm_db_missing_index_group_stats s

,sys.dm_db_missing_index_groups g

,sys.dm_db_missing_index_details d

where s.group_handle = g.index_group_handle

and d.index_handle = g.index_handle

--order by s.avg_user_impact desc

) b,

sys.databases a

where a.database_id=b.database_id

)c

order by 百分比收益 desc,unique_compiles desc