GQLDB provides built-in graph algorithms for analyzing graph structure and discovering patterns. These algorithms are called using the CALL algo.* syntax and can be combined with GQL queries.
Algorithm Categories:
| Category | Purpose | Examples |
|---|---|---|
| Centrality | Find important nodes | PageRank, Betweenness, Closeness, Degree |
| Community Detection | Discover clusters | Louvain, Label Propagation, Connected Components |
| Path Finding | Find routes | Dijkstra, BFS, DFS, A* |
| Similarity | Find similar nodes | Node Similarity, Jaccard, Cosine |
Algorithms are called using the CALL statement with YIELD to capture results:
GQLCALL algo.pageRank('Person', 'FOLLOWS') YIELD nodeId, score MATCH (p:Person) WHERE id(p) = nodeId RETURN p.name, score ORDER BY score DESC LIMIT 10
Most algorithms accept these parameters:
| Parameter | Description |
|---|---|
nodeLabel | Label of nodes to include |
edgeType | Type of edges to traverse |
direction | Edge direction: 'OUTGOING', 'INCOMING', or 'BOTH' |
writeProperty | Property name to store results on nodes |
Many algorithms can write results back to nodes:
GQL// Compute and store PageRank scores CALL algo.pageRank('Person', 'FOLLOWS', {writeProperty: 'pageRankScore'}) YIELD nodesProcessed // Later query by stored score MATCH (p:Person) WHERE p.pageRankScore > 0.5 RETURN p.name, p.pageRankScore ORDER BY p.pageRankScore DESC
Algorithms ending in .stream return results row by row without persisting:
GQL// Stream results CALL algo.pageRank.stream('Person', 'FOLLOWS') YIELD nodeId, score RETURN nodeId, score
See the following pages for detailed information:
