The Auto update statistics option, located under Database Properties, causes SQL Server to automatically update statistics when approximately 20% of the table data has changed.
Beginning with Microsoft SQL Server 2016 (13.x), statistics may be automatically updated when less than 20% of the table data has changed. For more information, see the AUTO_UPDATE_STATISTICS Option section of the Microsoft documentation on Statistics.
When this occurs, SQL Server uses the default sample percentage (10%) to perform the update. As a result, the sample size is often too small to capture a true representation of the data distribution. Additionally, this process (and SQL Server's periodic checks to see whether the process needs to be done) can cause overhead at inopportune times and may affect database performance.
The Auto Update Statistics option is enabled in Azure SQL Database and cannot be disabled.
Database Administrators are empowered to choose whether the Auto update statistics option is enabled or disabled. If the Auto update statistics database option is enabled, Database Administrators are encouraged to aggressively manage statistics to ensure that they are rarely (if ever) automatically updated and that they are always captured with a 100% sample.