How to define a good repository interface

I have the following situation:

I'm collecting data on hosts. Each host has collections of properties and statuses. and the hosts are gathered in groups.

Each group has a unique ID and each host has a unique ID

and all the groups are gathered in a single "repository".

I'm currently using the following data structure:

public class Host {
    private final Map<PropertyId, Property> properties;
    private final Map<StatusId, Status> statuses;
}

public class Group {
    private final Map<HostId, Host> hosts;
}

public class AllGroups {
    private final Map<GroupId, Group> groups;
}

This is currently implemented as a regular in memory data structure but I need to save all this in a data base. I want to define a good abstraction that would allow me:

• To read each item
• to create update and delete properties and statuses
• to add and delete hosts
• to delete groups

I read some posts regarding the repository pattern and it seems appropriate, but I can't figure out how to define the interfaces correctly

Should I have 1 repository interface? Or should I have separate interfaces for HostRepository, PropertyRepository StatusReporitory...