COUNTING BLOOM FILTER

Technologies are generally described for a scheme for computing a counting number of a keyword. In some examples, a method performed under control of a computing device may include obtaining a result of a j-th set of hash functions with regard to a key; marking a head marker into a bit array of a bloom filter based at least in part on the result of the j-th set of hash functions, if the j is zero; and marking a tail marker into the bit array of the bloom filter based at least in part on the result of the j-th set of hash functions, if the j is the same as or larger than 1.