Patent attributes
An example apparatus includes a first query processor to obtain a first hash key, first qualifier data and first value data associated with the first hash key, the first value data including a second hash key and a third hash key; a candidate qualifier to use the first value data to prequalify the first hash key as a candidate for subsequent signature processing associated with a first site signature, the candidate qualifier to: determine prequalification of the first hash key is successful in response to a determination that the second hash key matches a second site signature preceding the first site signature in time and that the third hash key matches a third site signature following the first site signature in time; and determine the prequalification of the first hash key is unsuccessful in response to a determination that at least one of the second hash key fails to match the second site signature or the third hash key fails to match the third site signature.
