Divide the RAM between Pagecache and Heap size

what are the factors that needs to be consider while allocating the space to PageCache and Heap.

Lets say i have 16GB of memory - how much do you suggest to allocate for page cache and Heap size.

Thanks,

This is not a simple question, there's rather a lot to say.

In the Neo4j documentation there are two sections on consideration and capacity planning for memory sizing of instances. That's the best place to look. The really short answer is that it depends on a lot of factors, such as the size of your graph on disk, the type of transactions you're running, how many indexes you have, and other factors.

https://neo4j.com/docs/operations-manual/current/performance/memory-configuration/#_considerations

Sizing hardware for databases is typically not the easiest thing you'll do, but there's a really big payoff in terms of performance you can get out of the system by doing this correctly.

Usually try to fit the store files in the page cache if possible.
But for real world concurrent usage also have at least 6-8G heap.