1. A method of processing a query command in a distributed computing system in which a plurality of database tables are stored on a plurality of nodes, different portions of at least one database table being stored on at least two of the nodes, the method comprising: storing a first portion of a first database table and a first portion of a second database table on a first node, and storing a second portion of a first database table and a second portion of a second database table on a second node; determining a join table definition in response to a query command, said join table definition identifying a subset of said first database table to include in executing said database query command; generating a first join table from said first portion of said first database table in accordance with said join table definition, and generating a second join table from said second portion of said first database table in accordance with said join table definition; transmitting said first join table to said second node, and transmitting said second join table to said first node; comparing said first portion of said second database table with said first join table, and comparing said second portion of said second database table with said second join table to generate a first intermediate results file; comparing said first portion of said second database table with said second join table, and comparing said second portion of said second database table with said first join table to generate a second intermediate results file; and generating a final results file from said first intermediate results file and said second intermediate results file.