1. A method comprising: for a query comprising a query block specifying a first join between a first table and a second table, making a first determination that the query block contains no post-join references to the second table to be processed after the first join, wherein the query block does not reference the second table in a SELECT, GROUP-BY, HAVING, or ORDER BY clause or subquery connecting or correlating conditions of the query block; wherein the first join is one of an outer join and a cross join; making a second determination that the query block is duplicate-insignificant; and in response to making the first determination and the second determination, transforming the query into a transformed query, wherein the second table is eliminated from a corresponding query block in the transformed query; wherein the method is performed by one or more computing devices.