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Statistics are critical metadata used by SQL Server’s query optimizer, which influence the selected execution plan for a query.
The optimizer obtains its knowledge of the data, its distribution, and the number of rows a given query is likely to return from the available statistics.
Find out when statistics were last updated and changes since the last update.
Use SQL Update Statistics’ point and click interface to initiate table and index statistics updates quickly and easily.
If you have AUTO_UPDATE_STATISTICS option turned on for the database the query optimizer will automatically determine when statistics might be out-of-date and then update them when they are used by a query.
Therefore, frequent statistics updates should be avoided.SQL Server can automatically maintain statistics, periodically refreshing them based on its tracking of data modifications.However, for some tables, such as those subject to significant changes in distribution, or those with skewed values, it’s possible that SQL Server’s automatic statistics update will be inadequate to maintain consistently high levels of query performance.Run on virtual machines hosted in the cloud, such as Windows on Azure Virtual Machine (VM) and Windows on Amazon Elastic Compute Cloud (EC2).If you care about SQL Server performance you need to take SQL Server Statistics into account.
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Statistics are lightweight and small objects which describe how data in SQL Server tables are distributed.