Results of a study into the scalability of the cityEHR database have been published in the proceedings of XML London, 2016. This conference is an annual two-day gathering of prominent XML practitioners and is the perfect forum to present and discuss methods for implementing large scale XML database systems, such as cityEHR.
In his paper entitled “Scalability of an Open Source XML Database for Big Data”, John Chelsom described experiments that evaluated the performance of the eXist database (the open source database used by cityEHR) when loaded with records for up to 20,000 patients and described the implementation of a federated search across multiple database nodes, allowing cityEHR to scale up potentially to millions of patient records.