Issue
A user may be experiencing performance issues when running SQL queries.
Product Line
Power Monitoring Expert 7.2.x
Power Monitoring Expert 8.x
Power Monitoring Expert 9.0
Power Monitoring Expert 2020
Power Monitoring Expert 2021
Power Monitoring Expert 2022
Power Monitoring Expert 2023
Environment
Power Monitoring Expert Software with either SQL Server Versions (2005- 2022)
Cause
Outdated statistics can make the SQL server choose a non-optimal execution plan causing undesirable slow response times for certain queries.
Resolution
*Warning: Irreparable database damage can occur. This procedure should only be performed by users familiar with SQL Server Management Studio. Databases should be backed up prior to performing this procedure.*
To identify tables within the database which have outdated statistics, the following query can be used.
SELECT OBJECT_NAME(id) AS Table_Name, st.[name] AS Tname, si.name,
STATS_DATE(id, indid) AS DateLastUpdate,rowmodctr rowsModifiedSinceLastUpdate
FROM sys.sysindexes AS si
INNER JOIN sys.[tables] AS st ON si.[id] = st.[object_id]
INNER JOIN sys.schemas AS ss ON st.[schema_id] = [ss].[schema_id]
WHERE STATS_DATE(id, indid)<=DATEADD(DAY,-1,GETDATE())
AND rowmodctr>10
ORDER BY[rowmodctr] DESC
Once you have identified tables with outdated statistics, the UPDATE STATISTICS statement can be used to
bring the statistics back up to date.
Udgivet til:Schneider Electric Danmark
