Dgraph: Query for total number of nodes

[peterstace]

Lots of users have asked for this feature (or some variant of it). New users may get a bad impression of Dgraph since it cannot currently support 'basic' operations that other graph databases have. The answer that a 'count all nodes' function doesn't scale well may not be satisfactory for people who don't understand the technical details as to why this is the case.

One solution that @pawanrawal and I discussed:

• Use the _predicate_ predicate to find all nodes. Then we can just return the count of those nodes.

[manishrjain]

Sounds good.

[srinathganesh1]

Current version is "v1.0.6", is this feature implemented or planned?

[manishrjain]

You should be able to run something like this to get the total number of nodes.

{ total(func: (has, "_predicate_") { count(uid) } }

@kdsgambhir : Can you test this, and document this in how to section?

[ghost]

This query gives you the total count of nodes in your data:

{
  total (func: has (_predicate_) ) {
    count(uid)
  }
} 

[manishrjain]

Being done in Ratel.

[koenvanderveen]

How is this done in v1.1? Since _predicate_ doesnt exist anymore.

[martinmr]

You could assign all you nodes to a dummy type, and then run.

{
  total (func: eq (dgraph.type, DummyType) ) {
    count(uid)
  }
}