st = connection.prepare("create index Idx_com_edge_attribute on com_edge_attribute (db_id_edge, db_id_attribute);",false);
st.stepThrough();
st.dispose();
st = connection.prepare("create index Idx_com_subgraph_vertex on com_subgraph_vertex(db_id_subgraph, db_id_vertex);",false);
st.stepThrough();
st.dispose();
st = connection.prepare("create index Idx_com_subgraph_edge on com_subgraph_edge(db_id_subgraph, db_id_edge);",false);
st.stepThrough();
st.dispose();
st = connection.prepare("create index Idx_com_graph_subgraph on com_graph_subgraph (db_id_graph, db_id_subgraph);",false);