Retrieving the change log for a contact takes ages for my client - maybe a response of 10 minutes to get just 79 records for one contact. The contact database has about 39K rows, but with about 950k rows in the civicrm_log table (there are lots of transactions). Logging is switched on, which at the time seemed a very attractive option.
Would adding an index help? I have defragged & optimised the civicrm_log table, but to no effect.