1/10th sample, S? Each of the s unique queries has a probability Ps = 1/10 to be selected: • an expected number of s/10 of those queries will be in S. ??? Vasiliki Kalavri | Boston University 2020 10 Kalavri | Boston University 2020 24 • A bit array of size n, where n is generally higher than the expected number of elements in the input • k independent and uniformly distributed hash functions, where The probability of false positives depends on the choice of k and n: • Let m be the number of expected elements: • If the allocated bits per element, n/m, is too small, the filter will fill up too

plans ordered by how much load shedding they will cause. • Each row contains a plan with • expected cycle savings • locations for drop operations • drop amounts • QoS effects (provided that

operations that process input streams and produce output streams. • Declarative languages specify the expected results of the computation rather than the execution flow. • Imperative languages are used to

?? Vasiliki Kalavri | Boston University 2020 14 Combining estimates • Average won’t work: The expected value of 2R is too large. • Median won’t work: it is always a power of 2, thus, if the correct