Hi,
Database objects stats should be up to date for making the right decision of SQL Server optimizer.
If database objects stats are not up to date then SQL Server database optimizer will make a wrong decision for execution plan of transaction.
You can check all database objects stats with following query.
SELECT
object_name(si.[object_id]) AS [TableName]
, CASE
WHEN si.[stats_id] = 0 then 'Heap'
WHEN si.[stats_id] = 1 then 'CL'
WHEN INDEXPROPERTY ( si.[object_id], si.[name], 'IsAutoStatistics') = 1 THEN 'Stats-Auto'
WHEN INDEXPROPERTY ( si.[object_id], si.[name], 'IsHypothetical') = 1 THEN 'Stats-HIND'
WHEN INDEXPROPERTY ( si.[object_id], si.[name], 'IsStatistics') = 1 THEN 'Stats-User'
WHEN si.[stats_id] BETWEEN 2 AND 1004 THEN 'NC ' + RIGHT('00' + convert(varchar, si.[stats_id]), 3)
ELSE 'Text/Image'
END AS [IndexType]
, si.[name] AS [IndexName]
, si.[stats_id] AS [IndexID]
, CASE
WHEN si.[stats_id] BETWEEN 1 AND 250 AND STATS_DATE (si.[object_id], si.[stats_id]) < DATEADD(m, -1, getdate())
THEN '!! More than a month OLD !!'
WHEN si.[stats_id] BETWEEN 1 AND 250 AND STATS_DATE (si.[object_id], si.[stats_id]) < DATEADD(wk, -1, getdate())
THEN '! Within the past month !'
WHEN si.[stats_id] BETWEEN 1 AND 250 THEN 'Stats recent'
ELSE ''
END AS [Warning]
, STATS_DATE (si.[object_id], si.[stats_id]) AS [Last Stats Update]
, no_recompute
FROM sys.stats AS si
WHERE OBJECTPROPERTY(si.[object_id], 'IsUserTable') = 1 and STATS_DATE (si.[object_id], si.[stats_id]) is not null
AND (INDEXPROPERTY ( si.[object_id], si.[name], 'IsAutoStatistics') = 1
OR INDEXPROPERTY ( si.[object_id], si.[name], 'IsHypothetical') = 1
OR INDEXPROPERTY ( si.[object_id], si.[name], 'IsStatistics') = 1)
ORDER BY [Last Stats Update]
go
Do you want to learn Microsoft SQL Server DBA Tutorials for Beginners, then read the following articles.
https://ittutorial.org/sql-server-tutorials-microsoft-database-for-beginners/