We're looking at various ways to counter growth of the civicrm database, and civicrm.civicrm_activity is a >100GB table. We may be able to selectively purge data from this table.

Tests:

Get an order of magnitude on the impact of purging data from column 'details'

• procedure:
  • create table civicrm_activity_test like civicrm_activity;
  • insert into civicrm_activity_test select * from civicrm_activity;
  • check size civicrm_activity_test.ibd (result: 104GB)
  • update civicrm_activity_test set details=null;
  • create table civicrm_activity_test2 like civicrm_activity_test;
  • insert into civicrm_activity_test2 select * from civicrm_activity_test;
  • check size of civicrm_activity_test2.ibd (result: 25GB)