To calculate the accuracy of an estimation, we compare the result to the exact cardinality of the QueryGraph in the DataGraph. To do this, a get_exact_size function is included in the ExactSizeCalculator.jl file: d = load_dataset("data.txt") q = load_queryset("query.txt") exact_card...
the data was received as a single event record and "items" is a list or array of elements. Each element in the array has its own set of coordinate
A power set is the collection of all subsets, empty set and the original set itself. Learn power set notation, cardinality and properties with examples. Find power set of the empty set at BYJU'S.
To be more specific, these classes might not contain the one estimation algorithm, rather they join together a set of specific algorithms and drive them. For example calculatorCSelCalcExpressionComparedToExpressionmay estimate join cardinality using join columns histograms in a different ways, depending ...
but there is a relevant difference. While in the 2014 CE we always used the single column statistics for each of the predicate columns, in 2016 CE, if multi-column statistics over the predicate columns are available, those will be used to derive estimations with a differen...