data-konzept

'When your SQL Server database is set to have its statistics automatically updated, you will probably conclude that, whenever the distribution statistics are out-of-date, they will be updated before the next query is executed against that index or table. Curiously, this isn't always the case. What actually happens is that the statistics only gets updated if  needed by the query optimiser to determine an effective query plan.'...

https://www.simple-talk.com/sql/t-sql-programming/when-auto_update_statistics-doesnt-happen/