  A streaming graph is a graph formed by a sequence of incoming edges with time
stamps. Unlike static graphs, the streaming graph is highly dynamic and time
related. In the real world, the high volume and velocity streaming graphs such
as internet traffic data, social network communication data and financial
transfer data are bringing challenges to the classic graph data structures. We
present a new data structure: double orthogonal list in hash table (Dolha)
which is a high speed and high memory efficiency graph structure applicable to
streaming graph. Dolha has constant time cost for single edge and near linear
space cost that we can contain billions of edges information in memory size and
process an incoming edge in nanoseconds. Dolha also has linear time cost for
neighborhood queries, which allow it to support most algorithms in graphs
without extra cost. We also present a persistent structure based on Dolha that
has the ability to handle the sliding window update and time related queries.
