problem

For each task a materialised view of the segment data is created. 

Here are multiple problems: The check if a view can be deleted is done for historical reasons on each login instead by cron daily. 

This leads to DB problems on some installations with a lot of small tasks and a a lot of logins per day. 

Also the views are created with myisam engine - which should be considered as deprecated. 

Implement the innodb usage with a feature switch so that we can try out the movement to innodb completly.

solution

Clean up segment views on cron daily only.