Integration of YAGO Ontology in the IQP Construction System to Support Efficient Query Construction Over a Large-scale Relational Database

Abstract

IQP query construction system empowers na¨ ıve database users to create their own structured queries in an interactive way, starting from simple keywords and refining the initial query using options automatically suggested by the system. In order to generate such query construction options, IQP makes use of the database internal structures such as database schema and keyword occurrence statistics. The efficiency and usability of IQP was experimentally confirmed for the middle-sized datasets such as IMDB and Lyrics. Freebase is a large-scale open-world database where users collaboratively create content over an open platform. Deployment of the IQP system on Freebase faces additional challenges as the schema of Freebase is big and the query construction options derived based on the Freebase schema only are not informative enough to enable an efficient query construction process. Recently, IQP was extended to enable more general ontology-based query construction options that summarize the database schema and speed up the query construction process. Currently, the implementation of IQP uses Freebase taxonomy, that includes about 100 Freebase-specific domains and several top-level categories. In order to further improve efficiency of the query construction proceess of IQP and to enable deployment of the system over large-scale databases that do not have a pre-defined ontology layer, we make use of YAGO ontology. YAGO can provide a basis to summarize database schema and to create an optimal query construction process for large-scale databases. In the first step, we develop schema mappings between the Freebase dataset and the YAGO ontology. Then, we present algorithms that enable efficient integration of the YAGO ontology in the query construction process of IQP. Moreover, we generalize implementation of IQP to enable integration of generic ontologies. Finally, we evaluate the effect of YAGO integration on the efficiency of the query construction process. Our evaluation results confirm that YAGO-based options improve efficiency of the query construction process.