1. A method in a computing device for forecasting frequency of a query, the frequency of the query being a number of times the query is submitted to a search engine during an interval, the method comprising: determining whether the query is time-dependent or time-independent by analyzing frequencies of the query during past intervals; when it is determined that the query is time-dependent, generating a time-dependent query model to predict the frequency of the query at a future interval, the time-dependent model being derived from the frequency of the query during the past intervals; generating a predicted frequency for the query during a future interval using the generated time-dependent query model; and storing an indication of the predicted frequency generated using the time-dependent query model; and; when it is determined that the query is time-independent, generating a time-independent query model to predict the frequency of the query at a future interval, the time-independent model being derived from the frequency of the query and the frequency of another query during the past intervals; and generating a predicted frequency of the query during a future interval using the generated time-independent query model; and storing an indication of the predicted frequency generated using the time-independent query model.