A method and system searches documents that contain an ordered pair of keywords using search indices stored in multiple storage locations. In one embodiment, a server receives the search request that includes an ordered pair of keywords. The server hashes each keyword with multiple hash functions to obtain a hash vector pair, which are used to index a chain of search indices. Hash values in the hash vector pair are used to locate the chain of search indices that are stored across multiple storage locations. The last search index in the chain provides identifiers of documents containing the ordered pair of keywords, with a distance between the keywords in the documents below a predetermined limit. The documents can be retrieved from document repositories using the identifiers.