Table statistics / index statistics generation
How often do you run/should system run table & index statistics through DBA calendar/BRtool? What impact on system load does it have? Do you run it for all tables & indecies above certain size?
It is better to run update statistics in your systems every week to get the Table statistics new.
By running update statistics regularly, you make sure that the database statistics are up-to-date, so improving database performance. You can schedule the checks in the Computing Center Management System of the SAP System, using the DBA Planning Calendar.
The Oracle cost-based optimizer (CBO) uses the statistics to optimize access paths when retrieving data for queries. If the statistics are out-of-date, the CBO might generate inappropriate access paths using the wrong index, resulting in poor performance.
It is better to run it when the load on the system is low, i.e., on Saturdays or Sundays.
You should run on all Tables.