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Conventional data warehouses employ the query- at-a-time model, which maps each query to a distinct physical plan. When several queries execute concurrently, this model introduces contention and thrashing, because the physical plans—unaware of each other—c ...
This paper approaches the incremental view maintenance problem from an algebraic perspective. We construct a ring of databases and use it as the foundation of the design of a query calculus that allows to express powerful aggregate queries. The query calcu ...
Database management systems (DBMS) provide incredible flexibility and performance when it comes to query processing, scalability and accuracy. To fully exploit DBMS features, however, the user must define a schema, load the data, tune the system for the ex ...
Intuitively, aggressive work sharing among concurrent queries in a database system should always improve performance by eliminating redundant computation or data accesses. We show that, contrary to common intuition, this is not always the case in practice, ...
Data-oriented scientific processes depend on fast, accurate analysis of experimental data generated through empirical observation and simulation. However, scientists are increasingly overwhelmed by the volume of data produced by their own experiments. With ...
We study highly expressive query languages such as datalog, fixpoint, and while-languages on probabilistic databases. We generalize these languages such that computation steps (e.g. datalog rules) can fire probabilistically. We define two possible semantic ...
A major obstacle to the development of ontologies in support of the Semantic Web is the poor capability of current ontology techniques to handle very large ontologies, in particular regarding scalability of reasoners. This paper builds on the assumption th ...
In standard database scenarios, an end-user assumes that all data (e.g., sensor readings) is stored in a database. Therefore, one can simply submit any arbitrary complex processing in the form of SQL queries or stored procedures to a database server. Data ...
This project proposes a new approach to interact with database systems through programming languages. A formal query language can be integrated within modern programming languages and the semi-structured queries can be evaluated using automatic transformat ...
We present DBToaster, a novel query compilation framework for producing high performance compiled query executors that incrementally and continuously answer standing aggregate queries using in-memory views. DBToaster targets applications that require effic ...
