To enable slow query logging, add 'logslow' => 1 to the 'dboptions' array in config.php. This will cause queries over 1 second (the '1' can be changed to any number of seconds) to be logged in the 'log_queries' table in the database.
Example
$CFG->dboptions = array ( 'dbpersist' => 0, 'dbport' => '', 'dbsocket' => '', 'logslow' => 1 ;
The 'log_queries' table can be exported and sent to Totara Support.
Most database administrations tools e.g. MySQL Workbench, PHPMyAdmin, etc., have a graphical user interface for this. You can also do this from the command line on the server.
I have included links to the MySQL, PostgreSQL and MSSQL documentation below and we will add this to our how-to article for logging slow queries.
Only enable slow query logging long enough to test slow queries and immediately disable after testing.