Tools for Optimizer Testing

SIGMOD 2019 Talk on Exact Cardinality Query Optimization


This line of work is targeted at supporting developers of query optimizers. To assess the quality of query optimizers (and to identify candidate areas for improvements), it is useful to compare plans produced by an optimizer to guaranteed optimal plans. Guaranteed optimal plans are difficult to find since we cannot rely on the optimizer cost or cardinality model. We are developing approaches to find guaranteed optimal plans via offline optimization. This requires executing plans or plan fragments to obtain guaranteed bounds on execution costs and intermediate result sizes.


Immanuel Trummer. "Exact cardinality query optimization with bounded execution cost." SIGMOD 2019.