title: Data extraction and ad hoc query of an entity-attribute-value database.
abstract: Entity--attribute--value (EAV) tables form the major component of several mainstream electronic patient record systems (EPRSs). Such systems have been optimized for real-time retrieval of individual patient data. Data warehousing, on the other hand, involves cross-patient data retrieval based on values of patient attributes, with a focus on ad hoc query. Attribute-centric query is inherently more difficult when data are stored in EAV form than when they are stored conventionally. The authors illustrate their approach to the attribute-centric query problem with ACT/DB, a database for managing clinical trials data. This approach is based on metadata supporting a query front end that essentially hides the EAV/non-EAV nature of individual attributes from the user. The authors' work does not close the query problem, and they identify several complex subproblems that are still to be solved.
authors.affiliation: Yale University, New Haven, Connecticut, USA. prakash.nadkarni@yale.edu
authors.forename: P M
authors.initials: PM
authors.lastname: Nadkarni
authors.forename: C
authors.initials: C
authors.lastname: Brandt
mesh_terms: D002986:Clinical Trials as Topic; D003628:Database Management Systems; D006801:Humans; D016247:Information Storage and Retrieval; D016347:Medical Records Systems, Computerized / Q000458:organization & administration*; D014584:User-Computer Interface