Title:
【発明の名称】関係データベースの限定述語処理方法
Document Type and Number:
Japanese Patent JP2836103
Kind Code:
B2
Abstract:
PURPOSE:To reduce the number of times of comparison and to improve speed for limited predicate processing by removing a row, which is equipped with the value of a column excepting for a sub inquiry result, from the row of main inquiry and sorting in the column designated by a definitive predicate. CONSTITUTION:A retrieval condition preparing part 101 prepares a condition expression 111 and a retrieval processing part 102 evaluates the condition expression 111. Then, an evaluated result is stored in a sub inquiry result 123. Elements with the overlapped same value is removed in an overlap removal sort part 103 and the sort is executed. Then, a sorting result is stored in an overlap removal/sort result stack 125 for the sub inquiry result. Next, a selection sort part 104 refers the stack 125 and executes the removal and sort of the row with the column from a main inquiry result stack 124. Then, a processing result is stored in a selection/sort result stack 126 for main inquiry result. A definitive predicate deciding part 105 executes the decision of the limited predicate by comparing the value of the column in the result stack 126 with the element of the result stack 125, and stores a retrieval result in a stack 127.
Inventors:
ITAKURA ICHIRO
NAKAMURA JINNOSUKE
TSUCHA YUKIHISA
HORIUCHI TAKASHI
NAKAMURA JINNOSUKE
TSUCHA YUKIHISA
HORIUCHI TAKASHI
Application Number:
JP16818689A
Publication Date:
December 14, 1998
Filing Date:
June 29, 1989
Export Citation:
Assignee:
NIPPON DENSHIN DENWA KK
HITACHI SEISAKUSHO KK
HITACHI SEISAKUSHO KK
International Classes:
G06F17/30; (IPC1-7): G06F17/30
Other References:
板倉，芳西，中村，「データベースプロセッサＲＩＮＤＡの副問合せ最適化方式」，情報処理学会第３８回（昭和６４年前期）全国大会講演論文集（▲ＩＩ▼），ｐ９５２−９５３（平１−３−１５）
Attorney, Agent or Firm:
Masatoshi Isomura