1. A method, implemented at a computer system that includes one or more processors, for performing a distributed data operation, the method comprising the computer system performing the following: receiving a request to perform one or more data operations, the one or more data operations being performed by at least some of a plurality of node endpoints, wherein each node endpoint of the plurality includes a partition of a sharded table; determining how many node endpoints are needed to satisfy the request, wherein the determination is at least partially based on information obtained from an updateable directory that is consulted in response to the request, the updateable directory detailing where each partition of the sharded table is located in each of the plurality of node endpoints such that the updateable directory maps the sharded table across the plurality of node endpoints; after determining how many node endpoints are needed to satisfy the request, servicing the request to perform the one or more data operations, wherein servicing the request to perform the one or more data operations includes: after determining how many node endpoints are needed to satisfy the request, select a particular set of node endpoints that will be used to service the request; from within the particular set, designate a particular node endpoint to act as a master node endpoint and designate each remaining node endpoint included within the particular set as slave node endpoints; and direct the request and all subsequent requests included within the session of requests to the master node endpoint.