Updating statistics sql 2016 r2
For samples statistics, only the sampled rows are imported.
If you have a large external table, it will be much faster to use the default sampling instead of the full scan option.
These statistics are used by the SQL Server Query Optimizer to determine the best plan to execute a query.You can specify any column that can be specified as an index key column with the following exceptions: For more information about the AUTO_STATISTICS_UPDATE option, see ALTER DATABASE SET Options (Transact-SQL).For more information about disabling and re-enabling statistics updates, see Statistics. If per partition statistics are not supported an error is generated.Only the first column is used for creating the histogram.All columns are used for cross-column correlation statistics called densities.