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; select a preprocessed search query from the plurality of preprocessed search queries to include into a search plan, wherein to select the preprocessed search query includes to: determine two or more preprocessed search queries of the plurality of preprocessed search queries that meet a precision requirement; and in response to the determination that two or more preprocessed search queries meet the precision requirement, select the preprocessed search query from the two or more preprocessed search queries to include in the search plan based at least in part on confidence levels associated with respective ones of the two or more preprocessed search queries; and input the search plan into 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.