我有一个GeocodedPoints表。我正在优化的这个查询尝试为经纬度位置提取匹配点。不幸的是它太慢了!优化边界框查询
该表基本上是边界框和相应地址的列表。它还包含精确边界框的DBGeography,但是,鉴于SQL在这种情况下的速度有多慢,我将它转化为.NET land并在那里查询DBGeography。
我的查询然后基本上看看是否在边界框内[由NESW指定]并返回结果。
在我看来,这应该是非常快,但唉,它并不像我想的那样快。
我对边界一个无唯一,非聚集索引和像这样
注意,因为我们只返回已修改在过去2结果UTC需要对UTC周。
我已经通过SQL事件探查器工具来运行这一点,这里的一些信息:
- 50万行该表
- 时间从每次通话
- 250-350ms范围从5-20k 读取范围
最后这里是我的查询使用
exec sp_executesql N'SELECT
[Project1].[ID] AS [ID],
[Project1].[CENTER] AS [CENTER],
[Project1].[BOUNDS] AS [BOUNDS],
[Project1].[UTC_UPDATED] AS [UTC_UPDATED],
[Project1].[PLACE_ID] AS [PLACE_ID],
[Project1].[FORMATTED_ADDRESS] AS [FORMATTED_ADDRESS],
[Project1].[POST_CODE] AS [POST_CODE],
[Project1].[SOURCE] AS [SOURCE],
[Project1].[North] AS [North],
[Project1].[East] AS [East],
[Project1].[South] AS [South],
[Project1].[West] AS [West]
FROM (SELECT
[Extent1].[ID] AS [ID],
[Extent1].[CENTER] AS [CENTER],
[Extent1].[BOUNDS] AS [BOUNDS],
[Extent1].[UTC_UPDATED] AS [UTC_UPDATED],
[Extent1].[PLACE_ID] AS [PLACE_ID],
[Extent1].[FORMATTED_ADDRESS] AS [FORMATTED_ADDRESS],
[Extent1].[POST_CODE] AS [POST_CODE],
[Extent1].[SOURCE] AS [SOURCE],
[Extent1].[North] AS [North],
[Extent1].[East] AS [East],
[Extent1].[South] AS [South],
[Extent1].[West] AS [West]
FROM [dbo].[HST_GEOCODE_POINTS] AS [Extent1]
WHERE ([Extent1].[UTC_UPDATED] > @p__linq__0) AND ([Extent1].[North] >= @p__linq__1) AND ([Extent1].[East] >= @p__linq__2) AND ([Extent1].[South] <= @p__linq__3) AND ([Extent1].[West] <= @p__linq__4)
) AS [Project1]
ORDER BY [Project1].[UTC_UPDATED] DESC, [Project1].[SOURCE] DESC',N'@p__linq__0 datetime2(7),@p__linq__1 float,@p__linq__2 float,@p__linq__3 float,@p__linq__4 float',@p__linq__0='2017-05-16 11:12:12.4425257',@p__linq__1=53.016466402998645,@p__linq__2=-1.715320912729779,@p__linq__3=53.016466402998645,@p__linq__4=-1.715320912729779
注意我的UTC当前是第一个在这个查询中,但最后在索引。具有讽刺意味的是,这似乎使我的查询速度更快,但每次调用都能达到20k次。
@GordonLinoff我不确定你的意思?我已经在桌面上有一个DBGeography,但不能用它查询太慢。 – Chris
注意从SQL Sentry Plan Explorer(一个免费工具)添加执行计划?这会有很大的帮助。 –
通常在两周内更新了多少行。如果没有那么多,它可能会*更有效率的日期列在索引中第一个... – user1429080