Custom XIDs for creating edges

Users Dgraph
1

I’m bulk-loading data into d-graph for an external source, as is. There’s a literal that uniquely identifies each node. Let’s call it “name”. Each node has a “name”. Some nodes (10% of the total) have a literal “targetName” that specifies “name” of another node to which do I need to create a “target” edge.
This is how I do it right now:

  1. Bulk load the data.
  2. Query for all nodes and return their "name"s and uids.
  3. Externally create a uid to “name” hash
  4. Query for all nodes (with a has(targetName) filter)
  5. Create the N-quad for each mutation, one at a time (using the hash, “name” and “targetName”)
  6. Live-load the generated RDF

Currently Step 2 here is killing my efficiency by orders of magnitude, and it is pretty redundant and suboptimal to go about. Is there a native dgraph functionality that can help me achieve this?

Given that I’m maintaining the uniqueness of “name” externally anyway, if I can use it as an xid identifier for live load mutations, that’ll be tremendously helpful but I’m not sure if XIDs serve that purpose.

2

Welcome @zmateen,

I am not sure if you have considered the upsert capability which might help in eliminating step 2 altogether.

Considering the schema :

<friend>: [uid] .
<friendName>: string @index(exact) .
<name>: string @index(hash) .

Consider a Person type as below. The name attribute is setup for identification, and friend is a relation between Person objects.

for1
for1789×381 13 KB

Given this, if you could create a mutation for each x <friend> y as below. It will try to match by name, and if not found, create either/both “x” and “y” node. “john” and “steve” can be replaced by the unique identifiers you are using.

upsert {
  # john friend steve
  query {
    findX(func: eq(name, "john")) {
      x as uid      
    }
    
   findY(func: eq(name, "steve")) {
      y as uid      
    }
  }
  mutation {
    set {
#     set types      
      uid(x) <dgraph.type> "Person" .
      uid(y) <dgraph.type> "Person" .
#     set relation friend      
      uid(x) <friend> uid(y) .
#     set attributes      
      uid(x) <name> "john" .
      uid(y) <name> "steve" .
    }
  }
}

You could load data directly through curl commands as mentioned here. You could also use the Ratel UI, it’s definitely more user friendly.

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