Heap size recomandation for Read only System

Hi,
I have 100GB size database .
What is the default heap size for 61GB RAM ? (The cache size is 50% but nothing written on the heap)
What is the recommanded value for Read-Only , few user with long queries ?
In case I only load data once, and have few users do I need large heap ?

Thanks!

Depends on your type of queries.

I'd probably go with 16G heap and 38G page-cache.