1. A method comprising: grouping single fields of a multiple-field source into a search target having multiple-field keys (MFKs) whose single fields correspond to the single fields in multiple-field vectors (MFVs) of entries in a data structure; generating a set of queries based, at least in part, on the MFKs, wherein each query has a different MFK as a lead MFK; using a query to determine whether the non-wildcard values in the MFVs of an entry match the non-wildcard values in corresponding MFKs of the search target; and using, if no entry has non-wildcard values in the MFVs that match the corresponding non-wildcard values in the MFKs, the queries to determine whether the entry has non-wildcard values in a MFV that match the non-wildcard values in a corresponding lead MFK, plus remaining MFVs that match corresponding remaining MFKs based on matching the non-wildcard values and wildcard values.