ObjectRank: Authority-Based Keyword Search in Databases

The ObjectRank system applies authority-based ranking to keyword search in databases modeled as labeled graphs. Conceptually, authority originates at the nodes (objects) containing the keywords and flows to objects according to their semantic connections. Each node is ranked according to its authority with respect to the particular keywords. One can adjust the weight of global importance, the weight of each keyword of the query, the importance of a result actually containing the keywords versus being referenced by nodes containing them, and the volume of authority flow via each type of semantic connection. Novel performance challenges and opportunities are addressed. First, schemas impose constraints on the graph, which are exploited for performance purposes. Second, in order to address the issue of authority ranking with respect to the given keywords (as opposed to Google’s global PageRank) we precompute single keyword ObjectRanks and combine them during run time. We conducted user surveys and a set of performance experiments on multiple real and synthetic datasets, to assess the semantic meaningfulness and performance of ObjectRank.