问题描述
sql Server 有一个关于索引的统计数据,它错误地估计了行数,这个表(和谓词)用于许多不同的查询。这会导致这些查询性能不佳,因为统计信息预计查询将返回 5 行,而它返回 431268。
查询:
SELECT COUNT(buildrecord.buildrecordID)
FROM dbo.buildrecord
WHERE buildrecord.ContainedToDT IS NULL
AND buildrecord.RfBuildrecordtypeID = 2
AND buildrecord.IsEdited = 0
昨天使用全扫描更新了统计数据:
索引有
在 buildrecord
表中,ContainedToDT
是一个 NULLABLE DATETIMEOFFSET
,RfBuildrecordtypeID
是一个 NOT-NULL SMALLINT
和 IsEdited
是一个非空 tinyint
。
索引如下:
CREATE NONCLUSTERED INDEX [IM_ContainedToDT_RfBuildrecordtypeID_IsEdited]
ON [dbo].[buildrecord] ([ContainedToDT] ASC,[RfBuildrecordtypeID] ASC,[IsEdited] ASC)
INCLUDE([InvPackCreatedID],[InvPackConsumedID])
WITH (PAD_INDEX = OFF,STATISTICS_norECOmpuTE = OFF,SORT_IN_TEMPDB = OFF,DROP_EXISTING = OFF,ONLINE = OFF,ALLOW_ROW_LOCKS = ON,ALLOW_PAGE_LOCKS = ON,OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY]
sql Server 版本为 Microsoft sql Server 2019 (RTM-CU8) (KB4577194) 兼容模式为 sql Server 2016 (130)
任何建议或想法将不胜感激。