Sharing heap memory with fork()

Question

I am working on implementing a database server in C that will handle requests from multiple clients. In order to do so I am using fork() to handle connections for individual cli

Answer 1

Would it suffice to share the root pointer of the database or do I have to make all allocated memory as shared?

No, because each process will have a its own private memory range. Copy-on-write is a kernel-space optimization that is transparent to user space.

As others have said, SHM or mmap'd files are the only way to share memory between separate processes.