I have understood that you should definitely try to keep the heap size under 32G as apparently the JVM can only compress pointers below that. Because we do even

I have understood that you should definitely try to keep the heap size under 32G as apparently the JVM can only compress pointers below that. Because we do event logging and our documents don't change after being indexed, some of the problems you mentioned (like merging) are not as pressing. And of course each log event has a timestamp and we can indeed limit our queries with them.