Update statistics
As with fragmented indexes, if the optimizer doesn’t have up-to-date information about the
distribution of key values (statistics) of table columns, it cannot generate optimal execution
plans. We recommend that you update the statistics for all tables on a regular basis. The
frequency of updates depends on the rate at which the database handles DML operations, but is
typically run twice a week during off peak hours. However, avoid updating statistics on the
days that you’re rebuilding indexes. For more information on updating statistics, see the
Microsoft SQL Server documentation
For database optimization, we recommend using an index and statistics maintenance script.
For an example, see the SQL Server
index and statistics maintenance script
