Statistics Update Clarification
By default statistics are created automatically within SQL Server. And, by default, these stats are updated automatically based on a set of triggers. The triggers are defined as If 0 rows - Any data added leads to a statistics update If < 500 rows - 500 rows added causes a stats update If > 500 rows - 500 rows + 20% of the number of rows causes a stats update (unless you enable a traceflag in 2012 in which case you get a proportional value instead of 20%). There are some exceptions for temporary tables and some variations for filtered statistics and filtered indexes, but you get the idea. I was writing an article on statistics in preparation for another Oracle/SQL Server discussion (on, you guessed it, statistics) and I…