有个计算公式,根据你的数据分布,WHERE条件,
SELECT COUNT(DISTINCT [ROW]) AS DistinctColVales,
COUNT([ROW]) AS NumberOfRows,
(CAST(COUNT(DISTINCT [ROW]) AS DECIMAL)
/CAST(COUNT([ROW])) AS Selectivity
FROM dbo.GridPoint_0
选择Selectivity 较高的优选创建。
报告相同问题?