In moodle config add in $CFG->dboptions array 'logall' => true Open few pages in moodle site verify new entry are loged in {log_queries} table check that in info filed there is php array with data explain how db engin run the quey and the error field is 0 replace   $CFG->dboptions  'logall' => true to 'logslow' => 0.001 and repeat steps 1-4 Change to differnet type of DB and return all the steps above