1. A method of query execution in a massively parallel processing (MPP) data storage system comprising a master node and a cluster of multiple distributed segments that access data in distributed storage, comprising: generating a self-described query plan at the master node that is responsive to a query, wherein the self-described query plan comprises metadata and other information needed by one or more segments to execute the self-described query plan, wherein the metadata and other information comprise information relating to locations of data in the distributed storage in connection with execution of the self-described query plan; communicating the self-described query plan to the one or more segments for execution; and receiving a result associated with execution of the self-described query plan from the one or more segments, wherein the self-described query plan is executed such that the one or more segments do not access a central metadata store in connection with executing the self-described query plan.