diff --git a/api/server/src/main/java/org/softwareheritage/graph/Dataset.java b/api/server/src/main/java/org/softwareheritage/graph/Dataset.java
index dda4917..410c13c 100644
--- a/api/server/src/main/java/org/softwareheritage/graph/Dataset.java
+++ b/api/server/src/main/java/org/softwareheritage/graph/Dataset.java
@@ -1,115 +1,125 @@
 package org.softwareheritage.graph;
 
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.zip.GZIPInputStream;
 
 import it.unimi.dsi.big.webgraph.BVGraph;
 import it.unimi.dsi.big.webgraph.LazyLongIterator;
 import it.unimi.dsi.fastutil.io.BinIO;
 import it.unimi.dsi.fastutil.longs.LongBigArrays;
 import it.unimi.dsi.fastutil.objects.Object2LongFunction;
 import it.unimi.dsi.io.FastBufferedReader;
 import it.unimi.dsi.io.LineIterator;
 import it.unimi.dsi.lang.MutableString;
 
 public class Dataset
 {
     public enum Name {
         DIR_TO_DIR,
         DIR_TO_FILE,
         DIR_TO_REV,
         ORIGIN_TO_SNAPSHOT,
         RELEASE_TO_OBJ,
         REV_TO_DIR,
         REV_TO_REV,
         SNAPSHOT_TO_OBJ
     }
 
     BVGraph graph;
     String path;
     HashMap<String, Long> hashToNode;
     HashMap<Long, String> nodeToHash;
 
     public Dataset(String datasetPath)
     {
         try {
             this.graph = BVGraph.load(datasetPath);
             this.path = datasetPath;
             setupNodesMapping();
         } catch (Exception e) {
             System.out.println("[WARNING] Could not load dataset " + datasetPath + ": " + e);
         }
     }
 
     void setupNodesMapping() throws IOException, ClassNotFoundException
     {
         this.hashToNode = new HashMap<String, Long>();
         this.nodeToHash = new HashMap<Long, String>();
 
         // First mapping: SWH hexhash (strings) <=> WebGraph MPH (longs)
         HashMap<Long, String> mphToHash = new HashMap<Long, String>();
         Object2LongFunction<String> mphMap =
             (Object2LongFunction<String>) BinIO.loadObject(path + ".mph");
 
         InputStream nodeFile = new FileInputStream(path + ".nodes.csv.gz");
         Collection<MutableString> hashes =
             new LineIterator(
             new FastBufferedReader(
             new InputStreamReader(
             new GZIPInputStream(nodeFile), "UTF-8"))).allLines();
 
         for (MutableString h : hashes)
         {
             String hash = new String(h.toString());
             long mph = mphMap.getLong(hash);
             mphToHash.put(mph, hash);
         }
 
         // Second mapping: WebGraph MPH (longs) <=> BFS ordering (longs)
         long n = mphMap.size();
         long[][] bfsMap = LongBigArrays.newBigArray(n);
         long loaded = BinIO.loadLongs(path + ".order", bfsMap);
         if (loaded != n)
             throw new IllegalArgumentException("Graph contains " + n + " nodes, but read " + loaded);
 
         // Create final mapping: SWH hexhash (strings) <=> BFS ordering (longs)
         for (long id = 0; id < n; id++)
         {
             String hash = mphToHash.get(id);
             long node = LongBigArrays.get(bfsMap, id);
 
             hashToNode.put(hash, node);
             nodeToHash.put(node, hash);
         }
     }
 
     public String getPath()
     {
         return path;
     }
 
     public long getNode(String hash)
     {
         return hashToNode.get(hash);
     }
 
     public String getHash(long node)
     {
         return nodeToHash.get(node);
     }
 
+    public long getNbNodes()
+    {
+        return graph.numNodes();
+    }
+
+    public long getNbEdges()
+    {
+        return graph.numArcs();
+    }
+
     public LazyLongIterator successors(long node)
     {
         return graph.successors(node);
     }
 
     public long outdegree(long node)
     {
         return graph.outdegree(node);
     }
 }