1. A method of processing data operations comprising: sending a request from an application to perform a data operation on a key-value data store, the request being in accordance with a first application-level protocol for performing the data operation on the key-value data store and including a first key of a first key-value pair used by a data storage system to perform the data operation; receiving the request at the data storage system, wherein the request is received by a key-value server that processes requests in accordance with the first application-level protocol for the key-value data store; performing first processing on the data storage system to perform the data operation in response to receiving the request at the data storage system, wherein said first processing uses a mapping table to map the first key to a first value that is a first data item corresponding to the first key, wherein the mapping table includes a plurality of entries for a plurality of key-value pairs including the first key-value pair, wherein each of the plurality of entries corresponds to an associated one of the plurality of key-value pairs and said each entry includes a first item that is a key of said associated one key-value pair and a second item that identifies a location of a data value of said associated one key-value pair, wherein said location of each of the plurality of entries varies in accordance with a policy; and returning a response to the application.