System and method for distributed SQL join processing in shared-nothing relational database clusters using stationary tables

摘要

System and method embodiments are provided for improving the performance of query processing in a massively parallel processing (MPP) database system by selecting one or more stationary tables for processing the query plan. In an embodiment method, a join query associated with a plurality of tables of the MPP database system is received at a coordinator process. Stationary tables are then selected from the tables according to table partition keys in the join query. The stationary tables are indicated and the join query are sent to a plurality of data nodes communicating with the coordinator process. At each of the data nodes, an execution plan for the join query is generated. Each of the data nodes then executes the execution plan to obtain query results without sharing information of the stationary tables between the data nodes.

主权项

1. A method for query processing in a massively parallel processing (MPP) database system, the method comprising:
receiving, at a coordinator process that runs on the MPP, a join query associated with a plurality of tables of the MPP database system; designating, from the tables to a plurality of processing nodes of the MPP, stationary tables and non-stationary tables, wherein the join query is processed by passing at least some information stored in the non-stationary tables between the processing nodes without passing any information stored in the stationary tables between the processing nodes; and executing, at each of the processing nodes, an execution plan to obtain query results, wherein executing the execution plan comprises passing at least some data stored in the non-stationary tables between the processing nodes without passing any information stored in the stationary tables between the processing nodes.