| 摘要 |
PURPOSE:To realize a high-speed processing system by scanning simultaneously relation to be joined together, comparing to decide whether a join field value is larger, smaller, or is equal, etc., to perform outer joining, and to produce the relation of result. CONSTITUTION:A relational data base processing mechanism 1 accepts an inquiry from a user and passes it to a relational operation control part 2. The relational operation control part 2 checks the adequacy of the inquiry. An execution control part 6 sorts and extracts relation operation to determine its execution procedure, which is passed to an interpretation execution part 3 and executed. Then, an outer joining execution part 10 performs outer joining processing. In outer join operation processing, the values of joint field are extracted and compared successively from the starting record of plural sort relation to generate outer joining result responding to the result decided to be larger, smaller or is equal, and the result is inserted into the relation of results. |
