Sql server 資料庫索引優化
阿新 • • 發佈:2021-01-20
一,查詢哪些資料庫缺失索引
SELECT DatabaseName = DB_NAME(database_id) ,[Number Indexes Missing] = count(*) FROM sys.dm_db_missing_index_details GROUP BY DB_NAME(database_id) ORDER BY 2 DESC;
二,查詢哪些庫,表缺失索引
SELECT [Total Cost] = ROUND(avg_total_user_cost * avg_user_impact * (user_seeks + user_scans),0) , avg_user_impact , TableName= statement , [EqualityUsage] = equality_columns , [InequalityUsage] = inequality_columns , [Include Cloumns] = included_columns FROM sys.dm_db_missing_index_groups g INNER JOIN sys.dm_db_missing_index_group_stats s ON s.group_handle = g.index_group_handle INNER JOIN sys.dm_db_missing_index_details dON d.index_handle = g.index_handle ORDER BY [Total Cost] DESC;
EqualityUsage :用 = 查詢列
InequalityUsage:用<> 查詢的列
Include Cloumns:用 in 查詢的列
三,新增對應的非聚集索引
CREATE NONCLUSTERED INDEX 索引名 ON 表名 ( EqualityUsage,InequalityUsage )include(Include Cloumns) WITH( STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY =OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO drop index 索引名 on 表名