What is the best practice to make use of relationships?

Users Dgraph
1

Hi, I am beginning to explore graph database and I am learning how to use Dgraph database. I wanted to play around so I tried to build a schema as follows

Datacenter → Servers → IpAddress → IpAddressPorts → Service

Each Datacenter can have many Servers
Each Server can have many IpAddresses
Each IpAddress can have many Ports
Each Port has a Service

I came up with the following schema


<HasServers>: [uid] @reverse .
<HasIpAddresses>: [uid] @reverse .
<HasIpPortNumbers>: [uid] @reverse .
<HasService>: uid @reverse .

<IpAddress>: string @index(exact) .
<Name>: string @index(exact) .
<PortNumber>: int .


type <Datacenter> {
	Name
	HasServers
}
type <Server> {
	Name
	HasIpAddresses
}
type <IpAddress> {
	IpAddress
	HasIpPortNumbers
}
type <IpPortNumber> {
	PortNumber
	HasService
}
type <DgraphDatabaseService> {
	Name
}

now to get the services of a Datacenter i can use this


servicesUnderDatacenter (func: type(Datacenter)){  
    uid
    Name
    HasServers{
    	uid
      Name
      HasIpAddresses{
        uid
        IpAddress
        HasIpPortNumbers{
          uid
          PortNumber
          HasService{
            uid
            Name
          }
        }
      }
    }
  }

to get the Datacenter of a Service i can use this

 datacenterOfService(func: type(DgraphDatabaseService)){  
    uid
    Name
  	~HasService {
  		uid
  		PortNumber
      ~HasIpPortNumbers {
        uid
        IpAddress
        ~HasIpAddresses {
          uid
          Name
          ~HasServers {
            uid
            Name
          }
        }
      }
		}
  }

So to go from Datacenter to service i got to traverse all the paths down and to get the Datacenter i traverse up.

The question is, is it the correct way to create the design of the relationships or should i include the “Datacenter” field in the “Service” Type so i have direct access to Datacenter?

Same to know the IpAddress and Port of the Service, should i include in the DgraphDatabaseService (type) the predicates UseIpAddress and UsePortNumber so i can get them more easily?

Am i making use of the “reverse” feature too much?

What is the best practice here?

2

You could use Recurse Query.

It is fine. If you add a “shortcut” edge, you would have to deal with future changes by yourself. It is fine to rely on just edges.

no, it is also fine.

As far I can see you are doing good from what you have shared.

Cheers.

1 Like
3

Amazing, thanks for the reply, as far as I researched I found that its not much of concern about performance when traversing through Types for Dgraph but I still was concerned about structure and about the “reverse” feature hitting performance.

Thanks again

4

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