1. A parallel processing database system, comprising: a master node comprising a processor and a database catalog, wherein the database catalog includes metadata defining database objects, and wherein the master node is configured to receive a query from a client node, to obtain metadata from the database catalog using a catalog server session that is established in connection with the query, to send one or more query plans and corresponding metadata to one or more of a plurality of worker nodes, to receive a request from a first worker node of the one or more of the plurality of worker nodes, the request being for additional metadata to be used in connection with execution of the corresponding query plan, and to obtain the additional metadata from the database catalog using the catalog server session that was established in connection with the query in response to receiving the request for additional metadata, wherein the request is received from the first worker node in the event that the first worker node determines that received corresponding query metadata is not sufficient to execute the corresponding query plan, and in the event that at least one other worker node of the plurality of worker nodes is queried for the additional metadata and the at least one other worker node does not have the additional metadata; and the plurality of worker nodes in communication with the master node, wherein one or more of the plurality of worker nodes receive a corresponding query plan and corresponding query metadata from the master node, and wherein the one or more of the plurality of worker nodes are configured to use the corresponding query metadata received from the master node in connection with execution of the corresponding query plan.