Index to speed up eventlog

Here is an index to speed up eventlog in some cases

I had one query taking 22 minutes!! Now taking 4 seconds - but this is an extreme example.

Usually they went from around 10-20 seconds to around 1s

(yeah we have many events on ports)

ALTER TABLE `observium`.`eventlog` ADD INDEX `entity` (`entity_type`, `entity_id`);

Happy new year!