17. The computer-readable medium of claim 16 , wherein the operations further comprise: in response to determining that the request modifies data on the primary data server, notifying the fast query service engine that contents of an answer set referencing the modified data, as maintained in the in-memory data storage at the fast query service engine, has become invalid.
16. The computer-readable medium of claim 15 , wherein the operations further comprise: in response to determining that the request is not supported by the fast query service engine, directing the request to the primary data server; and determining whether the request modifies data on the primary data server.