1. A computer based search server comprising: a memory; a processor configured to execute instructions stored in the memory, the instructions configured to cause the processor to: receive a search term; search an inverted index stored in the memory using the search term to obtain one or more document numbers associated by the inverted index with the search term, the one or more document numbers further associated with one or more corresponding documents that include the search term; retrieve one or more rank values for the documents from a fixed-width field array stored in the memory, wherein each array position corresponds to one of the document numbers, and the rank value of each document number is stored at the array position that corresponds to the document number, and wherein the rank values specify an ordering of the document numbers and are indexed in the fixed-width field array by the document numbers; and provide search results comprising indicia of the one or more corresponding documents ordered in accordance with the rank values.