Minor Description
In our Syncope installation (1.1.3 on Tomcat/MySQL) we observed long execution times (>1s) for TaskDAO.findToExec(), which is called periodically from NotificationJob to determine which notifications should be sent.
According to our analysis, this is due to the fact that TaskDAO.findToExec() performs a full scan on all entries of the task table with DTYPE="NotificationTask" (which could be a large number as all executed tasks are kept), although only very few tasks are selected (those with executed=0).
Creating an index on task.executed solved this problem; attached is a corresponding patch against the branch 1.1.X.