SQL SERVER 可以提供性能的语法

SELECT
avg_user_impact AS average_improvement_percentage,
avg_total_user_cost AS average_cost_of_query_without_missing_index,
‘CREATE INDEX ix_‘ + [statement] +
ISNULL(equality_columns, ‘_‘) +
ISNULL(inequality_columns, ‘_‘) + ‘ ON ‘ + [statement] +
‘ (‘ + ISNULL(equality_columns, ‘ ‘) +
ISNULL(inequality_columns, ‘ ‘) + ‘)‘ +
ISNULL(‘ INCLUDE (‘ + included_columns + ‘)‘, ‘‘)
AS create_missing_index_command
FROM sys.dm_db_missing_index_details a INNER JOIN
sys.dm_db_missing_index_groups b ON a.index_handle = b.index_handle
INNER JOIN sys.dm_db_missing_index_group_stats c ON
b.index_group_handle = c.group_handle
WHERE avg_user_impact > = 40