| 摘要 |
PURPOSE:To improve the join processing efficiency by applying in advance the conditions of application which are known in each phase of the reduction processing. CONSTITUTION:The given conditions are preset at first within a conditions buffer 19. The contents of the buffer 19 are replaced with more effective conditions every time more effective conditions are extracted at input phase processing parts 22 and 23, sort phase processing parts 24 and 25, output phase processing parts 26 and 27, etc. While condition filters 13-18 refer to the contents of the buffer 19 and transmit only a tuple that is coincident with desired conditions. The tuple which is not coincident with said conditions is disused. |
