1. A system for providing search results, comprising: one or more processors configured to: determine a search label corresponding to a search query; determine a plurality of preprocessing functions and an execution sequence in which at least some of the plurality of preprocessing functions are to be performed on the search query based at least in part on the search label corresponding to the search query; perform the plurality of preprocessing functions on the search query to obtain a plurality of preprocessed search queries; determine a preprocessed search query from the plurality of preprocessed search queries to include into a search plan; and input the search plan to a search engine to obtain the search results; and one or more memories coupled to the one or more processors and configured to provide the one or more processors with instructions.