ArrayQL for Linear Algebra within Umbra

Array database systems offer a declarative language for array-based access on multidimensional data. This study explains the integration of ArrayQL inside a relational database system, either addressable through a separate query interface or integrated into SQL as user-defined functions. With a relational database system as the target, we inherit the benefits such as query optimisation and multi-version concurrency control by design. Apart from SQL, having another query language allows processing the data without extraction or transformation out of its relational form. This is possible as we work on a relational array representation, for which we translate each ArrayQL operator into relational algebra. In our evaluation, ArrayQL within Umbra computes matrix operations faster than state of the art database extensions.