Techniques herein optimize subgraph pattern matching. A computer receives a graph vertex array and a graph edge array. Each vertex and each edge has labels. The computer stores an array of index entries and an array of edge label sets. Each index entry corresponds to a respective vertex originating an edge and associates an offset of the edge with an offset of the respective vertex. Each edge label set contains labels of a respective edge. The computer selects a candidate subset of edges originating at a current vertex. The edge labels of each candidate edge of the candidate subset include a same particular query edge labels. The computer selects the candidate subset based on the index array and afterwards selects a result subset of vertices from among the terminating vertices of the candidate edges. The labels of each vertex of the result subset include a same particular query vertex labels.