Historical Graph Management in Dynamic Environments

Abstract

Since dynamic graph data continuously change over time, it is necessary to manage historical data for accessing a snapshot graph at a specific time. In this paper, we propose a new historical graph management scheme that consists of an intersection snapshot and a delta snapshot to enhance storage utilization and historical graph accessibility. The proposed scheme constantly detects graph changes and calculates a common subgraph ratio between historical graphs over time. If the common subgraph ratio is lower than a threshold value, the intersection snapshot stores the common subgraphs within a time interval. A delta snapshot stores the subgraphs that are not contained in the intersection snapshot. Several delta snapshots are connected to the intersection snapshot to maintain the modified subgraph over time. The efficiency of storage space is improved by managing common subgraphs stored in the intersection snapshot. Furthermore, the intersection and delta snapshots can be connected to search a graph at a specific time. We show the superiority of the proposed scheme through various performance evaluations.