OverviewDatabases are a prerequisite part of any research endeavor that needs to maintain, integrate and share biomedical data. The relational database model, which was developed in the early 1970s, is now the most common type of commercial database model in use. Relational databases are employed in many scientific domains, from large-scale bioinformatics projects to clinical research systems. By archiving the results of experimental and observational studies, these projects serve as vital resources for ongoing data-driven biomedical research. However, relational databases provide limited abilities to query, discover and maintain clinical or biological knowledge about temporal patterns among research data. Biomedical researchers that work with temporal data must thus develop their own custom subsystems to deal with these queries. For applications with complex temporal query requirements, the writing of these subsystems often requires the development of complex custom temporal models, temporal query languages and a temporal query engines. Thousands of biomedical applications per year must reinvent the wheel in the development of these temporal query systems. In developing Chronus our, aim was to provide a standard way of expressing and executing temporal queries that deal with relational data. Chronus is a tool that provides a rich SQL-based temporal query language to write temporal queries. It also provides a temporal model that governs how temporal data should be stored in relational databased to facilitate analysis. It can be used directly to write temporal queries or can be embedded in applications and serve as the basis of a the temporal analysis substems in these applications. It is a general putrpose tool that works with standard relational databases and is not tied to any particular domain. |