查询统计
现在我们来粗略地看下直方图的工作方式，重要的是要了解如何查询表中的统计个数，幸运的是可以使用以下命令来查询：
AS Table_Name,
AS Column_Name,
AS Stats_Name
FROM sys.stats
JOIN sys.stats_columns
ON stats.object_id = stats_columns.object_id
AND stats.stats_id = stats_columns.stats_id
JOIN sys.columns
ON stats_columns.object_id = columns.object_id
AND stats_columns.column_id = columns.column_id
JOIN sys.objects
ON stats.object_id = objects.object_id
JOIN sys.indexes
ON sys.stats.Name = sys.indexes.Name
'U'
'Tab1'
BY Table_Name
18: GO