Question

是否需要在提瓜表之后更新表格统计数据,还是自动更新?

Q: 是否需要在表格上打字之后叫“UPD STATISTICS”吗?

Answer 1

Stats are not automatically updated until the stats are needed again. aka, the TRUNCATE does not do it. So "No".

最初的答复是“是”,因为它不是自动的,是北塞浦路斯土耳其共和国的一部分。这取决于你如何理解问题:-

除此以外,如果需要询问,统计数据就会自动更新(例如增长变化次数)。 http://msdn.microsoft.com/en-us/library/ms190397(SQL.90).aspx“rel=“noreferer”>Index Statistics

每当查询执行计划所用的统计数据未能对当前统计数据进行测试时,就开始统计更新。

http://msdn.microsoft.com/en-us/library/ms190330(SQL.90).aspx”rel=“noreferer” STATS_DATE

SELECT
   name AS index_name, 
   STATS_DATE(object_id, index_id)
FROM
   sys.indexes 
WHERE
   object_id = OBJECT_ID( MyTruncatedTable )

Edit: I wanted to make I sure :-)

页: 1

IF OBJECT_ID( dbo.foo ) IS NOT NULL DROP TABLE dbo.foo
CREATE TABLE dbo.foo (
    bar int NOT NULL IDENTITY (1, 1) PRIMARY KEY,
    thing int NOT NULL
)
CREATE INDEX IX_thing ON dbo.foo (thing)

INSERT dbo.foo (thing) SELECT c1.object_id FROM sys.columns c1, sys.columns c2
SELECT
   name AS index_name, 
   STATS_DATE(object_id, index_id) AS AfterLoad
FROM sys.indexes WHERE object_id = OBJECT_ID( dbo.foo )

SELECT DISTINCT thing FROM dbo.foo ORDER BY thing DESC
SELECT
   name AS index_name, 
   STATS_DATE(object_id, index_id) AS AfterFirstQuery
FROM sys.indexes WHERE object_id = OBJECT_ID( dbo.foo )

DELETE TOP (50000) dbo.foo
SELECT
   name AS index_name, 
   STATS_DATE(object_id, index_id) AS AfterDelete
FROM sys.indexes WHERE object_id = OBJECT_ID( dbo.foo )

SELECT DISTINCT thing FROM dbo.foo ORDER BY thing DESC
SELECT
   name AS index_name, 
   STATS_DATE(object_id, index_id) AS After2ndQuery
FROM sys.indexes WHERE object_id = OBJECT_ID( dbo.foo )

TRUNCATE TABLE dbo.foo
SELECT
   name AS index_name, 
   STATS_DATE(object_id, index_id) AS AfterTruncate
FROM sys.indexes WHERE object_id = OBJECT_ID( dbo.foo )

SELECT DISTINCT thing FROM dbo.foo ORDER BY thing DESC
SELECT
   name AS index_name, 
   STATS_DATE(object_id, index_id) AS After3rdQuery
FROM sys.indexes WHERE object_id = OBJECT_ID( dbo.foo )

Answer 2

这取决于贵国管理人员如何配置统计数据。通常的做法是每周的维修工作。然后,你要么等待工作,要么手工更新统计数据。

还可选择

When the automatic update statistics option, AUTO_UPDATE_STATISTICS, is on, the query optimizer determines when statistics might be out-of-date and then updates them when they are used by a query.

这可能在拖拉后重新计算。

您可以转而处理诸如:

ALTER DATABASE AdventureWorks
    SET AUTO_UPDATE_STATISTICS ON;

http://msdn.microsoft.com/en-us/library/ms187348.aspx”rel=“noreferer” 人工:

UPDATE STATISTICS Sales.SalesOrderDetail

2. 核实您目前的统计年龄:

SELECT 
    object_name = Object_Name(ind.object_id),
    IndexName = ind.name,
    StatisticsDate = STATS_DATE(ind.object_id, ind.index_id)
FROM SYS.INDEXES ind
order by STATS_DATE(ind.object_id, ind.index_id) desc

Answer 3

由于您有无数据,在数据插入之前,这种数据将毫无意义,然后你将设法更新数据。

不要忘记,你可以自动更新统计数据,每天/每周管理和更新统计数据......

如果对此仍然有重大关切,那就不必打字,然后更新表格中的数据。

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