apoc.meta.graph

Procedure APOC Core

apoc.meta.graph - examines the full graph to create the meta-graph

Signature

apoc.meta.graph(config = {} :: MAP?) :: (nodes :: LIST? OF NODE?, relationships :: LIST? OF RELATIONSHIP?)

Input parameters

Name	Type	Default
config	MAP?	{}

Name

Type

Default

config

MAP?

{}

Config parameters

The procedure support the following config parameters:

Table 1. Config parameters
name	type	default	description
sample	Long	1000	number of nodes to sample per label. See "Sampling" section below.
maxRels	Long	100	number of relationships to be analyzed, by type of relationship and start and end label, in order to remove / add relationships incorrectly inserted / not inserted by the sample result.

Sampling

Because the count stores return an incomplete picture of the data, we have to cross check the results with the actual data to filter out false positives.

We use a subset of the data to analyze by specifying the sample parameter (1000 by default).

Through this parameter, for each label we split data for each node-label into batches of (total / sample) ± rand where total is the total number of nodes with that label and rand is a number between 0 and total / sample / 10.

So, we pick a percentage of nodes with that label of roughly sample / total * 100% to check against. We pick the first node of each batch, and we analyze the properties and the relationships.

Output parameters

Name	Type
nodes	LIST? OF NODE?
relationships	LIST? OF RELATIONSHIP?

Name

Type

nodes

LIST? OF NODE?

relationships

LIST? OF RELATIONSHIP?

Usage Examples

The examples in this section are based on the following sample graph:

CREATE (Keanu:Person {name:'Keanu Reeves', born:1964})
CREATE (TomH:Person {name:'Tom Hanks', born:1956})

CREATE (TheMatrix:Movie {title:'The Matrix', released:1999, tagline:'Welcome to the Real World'})
CREATE (TheMatrixReloaded:Movie {title:'The Matrix Reloaded', released:2003, tagline:'Free your mind'})
CREATE (TheMatrixRevolutions:Movie {title:'The Matrix Revolutions', released:2003, tagline:'Everything that has a beginning has an end'})
CREATE (SomethingsGottaGive:Movie {title:"Something's Gotta Give", released:2003})
CREATE (TheDevilsAdvocate:Movie {title:"The Devil's Advocate", released:1997, tagline:'Evil has its winning ways'})

CREATE (YouveGotMail:Movie {title:"You've Got Mail", released:1998, tagline:'At odds in life... in love on-line.'})
CREATE (SleeplessInSeattle:Movie {title:'Sleepless in Seattle', released:1993, tagline:'What if someone you never met, someone you never saw, someone you never knew was the only someone for you?'})
CREATE (ThatThingYouDo:Movie {title:'That Thing You Do', released:1996, tagline:'In every life there comes a time when that thing you dream becomes that thing you do'})
CREATE (CloudAtlas:Movie {title:'Cloud Atlas', released:2012, tagline:'Everything is connected'})

CREATE (Keanu)-[:ACTED_IN {roles:['Neo']}]->(TheMatrix)
CREATE (Keanu)-[:ACTED_IN {roles:['Neo']}]->(TheMatrixReloaded)
CREATE (Keanu)-[:ACTED_IN {roles:['Neo']}]->(TheMatrixRevolutions)
CREATE (Keanu)-[:ACTED_IN {roles:['Julian Mercer']}]->(SomethingsGottaGive)
CREATE (Keanu)-[:ACTED_IN {roles:['Kevin Lomax']}]->(TheDevilsAdvocate)

CREATE (TomH)-[:ACTED_IN {roles:['Joe Fox']}]->(YouveGotMail)
CREATE (TomH)-[:ACTED_IN {roles:['Sam Baldwin']}]->(SleeplessInSeattle)
CREATE (TomH)-[:ACTED_IN {roles:['Mr. White']}]->(ThatThingYouDo)
CREATE (TomH)-[:ACTED_IN {roles:['Zachry', 'Dr. Henry Goose', 'Isaac Sachs', 'Dermot Hoggins']}]->(CloudAtlas);

CALL apoc.meta.graph()

Figure 1. Meta Graph