Thank you for the reply. This solutions works.
My feeling is that this will only work till the max value of this BIGINT is reached.
What is important to know is that a
new 'rp_id' is created when I update a iCal calendar which contains a repeated event. Because is update this every 5 minutes (to keep everything in sync), eventually the 'rp_id' will reach it limit. Is there a way to "reuse" unused rp_id's?