1. A method comprising, by one or more computing devices: accessing a first set of archived queries of an online social network received from a plurality of users of the online social network, each query being of a particular type of query; parsing each query in the first set of queries using a first parsing algorithm to generate a query command based on each query, each query command comprising one or more query constraints, each query constraint being for a specified number of objects of a specified object-type as specified by one or more parsing-configuration parameters of the first parsing algorithm, wherein the parsing-configuration parameters specify, for each particular type of query, instructions for generating a query command based on the type of query comprising a specified number of query constraints for a specified number of objects of a specified object-type to be retrieved from a specified number of data stores for that type of query; retrieving, for each query constraint of each query command, the specified number of objects that match at least a portion of the query constraint from one or more data stores, each data store storing one or more objects associated with the online social network of the specified object-type for the query constraint; scoring, for each query command, each retrieved object based on a first scoring algorithm; generating one or more revised parsing-configuration parameters based on a comparison of the scores of the retrieved objects and the specified number of objects of the query constraints; and revising the first parsing algorithm based on the parsing-configuration parameters, wherein one or more of the specified number of objects of a specified object-type is reduced based on the revised parsing-configuration parameters.