As per, https://github.com/openstack/nova/blob/master/nova/scheduler/filters/ram_filter.py#L48-L53 (https://github.com/openstack/nova/blo...)

    memory_mb_limit = total_usable_ram_mb * ram_allocation_ratio
    used_ram_mb = total_usable_ram_mb - free_ram_mb
    usable_ram = memory_mb_limit - used_ram_mb

In which nova table can i find total_usable_ram_mb, memory_mb_limit & total_usable_ram_mb ? the remaining details can be found in compute_nodes table.

Or does column memory_mb = total_usable_ram_mb ? in compute_node table