1. A query processing method, performed by a search engine server system, comprising: receiving, from a client system distinct from the search engine server system, a search query having one or more query terms; identifying a set of documents in accordance with the search query; generating a content snippet corresponding to content in a respective document of the identified set of documents, the content snippet associated with at least one query term of the one or more query terms in the search query; and returning to the client system a response to the search query, the response including information identifying at least the respective document and including the content snippet of the respective document; wherein generating the content snippet comprises: receiving a set of first token identifiers from a compressed document repository, the set of first token identifiers having a range of positions in the compressed document repository corresponding to positions at which a subset of the respective document is stored in the repository; performing a first decompression operation by applying one or more first mappings to the set of first token identifiers to provide a set of second token identifiers; and performing a second decompression operation by applying a second mapping to the set of second token identifiers to recover uncompressed content comprising a portion of the respective document.