1. A method for providing search results, comprising: receiving a search query; determining, using a processor, a plurality of preprocessing functions to be performed on the search query, based at least in part on a search label corresponding to the search query, wherein the search label is associated with a mapping to the plurality of preprocessing functions and a mapping to an execution sequence of the plurality of preprocessing functions, wherein the execution sequence describes an order in which at least some of the plurality of preprocessing functions are to be performed; performing the plurality of preprocessing functions on the search query based at least in part on the execution sequence to obtain a plurality of preprocessed search queries; generating, based at least in part on precision levels associated with the plurality of preprocessed search queries, a search plan, wherein generating the search plan includes selecting, from the plurality of preprocessed search queries, a preprocessed search query that meets a precision requirement to include in the search plan and a preprocessed search query that does not meet the precision requirement to exclude from the search plan, wherein the precision requirement is determined based on historical data; and inputting the search plan to a search engine to obtain the search results.