GShop: Towards Flexible Pricing for Graph Statistics

The prevalence of online query services in human life has attracted significant interest from the fields of economics and databases in determining appropriate pricing for such services. Simultaneously, the utilization of graph analytics across various domains has resulted in substantial social and economic benefits in recent years. As the adoption of graph analytics continues to expand, there is a corresponding need to establish fair pricing models for the information contributed by each participant in the data ecosystem. However, current query-based pricing frameworks cannot be applied to price graph statistics, as they fail to consider buyers' affordability and prevent arbitrage trading. To address this gap, in this paper, we propose a novel framework GSHOP for pricing graph statistic queries. Instead of pricing a precise answer for a query, our framework offers the flexibility to price a set of answers injected with noise. Based on the framework, data owners initially create and publish extended local views (ELVs) to represent their graph data. Additionally, it allows buyers to tolerate a certain degree of noise added to the answer to reduce their payments. The framework accurately quantifies the relationship between noise and price to ensure that payment and compensation are reasonable for the buyer and owners, respectively. We also propose algorithms specifically designed for fundamental graph statistics, including node degrees and subgraph counts such as k-stars and k-cliques. Furthermore, we formally prove that the pricing framework is arbitrage-free. Extensive experimental results on real-life graph data validate the good performance of the proposed framework and algorithms.