1. A method for processing database queries in a database system, comprising: performing a query that comprises memory intensive query operators and non-memory intensive query operators with a predetermined first memory allocation to a resource queue of the database system which performs said query; assigning said non-memory intensive query operators a pre-set first portion of said first memory allocation and assigning a remaining second portion of said first memory allocation for the memory intensive query operators of said query; receiving an indication that a memory intensive query operator of said query spilled to a storage device; computing a new second portion of said predetermined first memory allocation for the memory intensive query operators based on the indication; and dynamically adjusting the second portion of the first memory allocation assigned to said memory intensive query operators in accordance with the computed new second portion.