Virtually every commercial query optimizer chooses the best plan for a query using a cost model that relies heavily on accurate cardinality estimation. Cardinality estimation erro...
Volker Markl, Vijayshankar Raman, David E. Simmen,...
Progressive Optimization (POP) is a technique to make query plans robust, and minimize need for DBA intervention, by repeatedly re-optimizing a query during runtime if the cardina...
Vijayshankar Raman, Volker Markl, David E. Simmen,...
This paper introduces a new family of Generic and Progressive algorithms (GPAC, for short) for continuous mobile queries over mobile objects. GPAC provides a general skeleton that...
Estimates of predicate selectivities by database query optimizers often differ significantly from those actually encountered during query execution, leading to poor plan choices a...
Federated queries are regular relational queries accessing data on one or more remote relational or non-relational data sources, possibly combining them with tables stored in the ...
Stephan Ewen, Holger Kache, Volker Markl, Vijaysha...