1. A system for classifying a query in relation to one or more indexes to which the query is to be directed, comprising: one or more computer memories that store data relating to at least one index; and at least one processor coupled to the one or more computer memories, the at least one processor configured to act as: a feature generation component that generates one or more features corresponding to a query; a model building component that builds a prediction model for respective queries by utilizing a machine learning algorithm and an associated set of training data; and a predicting component that analyzes the one or more features corresponding to the query and the prediction model to predict whether the query is directed to a resource pre-designated as a commonly queried resource or a resource pre-designated as an uncommonly queried resource.