Cost-based query optimizers need to estimate the selectivity of conjunctive predicates when comparing alternative query execution plans. To this end, advanced optimizers use multi...
Volker Markl, Nimrod Megiddo, Marcel Kutsch, Tam M...
Current methods for selectivity estimation fall into two broad categories, synopsis-based and sampling-based. Synopsis-based methods, such as histograms, incur minimal overhead at ...
: Cost-based optimizers in relational databases make use of data statistics to estimate intermediate result cardinalities. Those cardinalities are needed to estimate access plan co...
In a variety of applications ranging from optimizing queries on alphanumeric attributes to providing approximate counts of documents containing several query terms, there is an in...
Zhiyuan Chen, Flip Korn, Nick Koudas, S. Muthukris...
Abstract. Good estimates of join result sizes are critical for query optimization in relational database management systems. We address the problem of incrementally obtaining accur...