GENERALIZED KEY INDEX
    1.
    发明专利

    公开(公告)号:JPH10143538A

    公开(公告)日:1998-05-29

    申请号:JP18194797

    申请日:1997-07-08

    Abstract: PROBLEM TO BE SOLVED: To provide a new index in a relational data base system. SOLUTION: A generalized key index is capable of index the first table of a relational data base through the use of an index key and an index condition. One or both of the index key and the index condition can refer to the many tables of the data base and or else, expression can use the field of at least one table excepting of the first table. The generalized key index directly correlate a generalized index key value with the recording identifier of the recording of the first table to make storage and data retrieval efficient.

    METHOD AND DEVICE FOR EXECUTING CONNECTION QUESTION IN DATA BASE SYSTEM

    公开(公告)号:JPH10320423A

    公开(公告)日:1998-12-04

    申请号:JP9482898

    申请日:1998-04-07

    Abstract: PROBLEM TO BE SOLVED: To generate a response to a connection by using a map for erasing a segment which can not satisfy a connected predicate. SOLUTION: A connection has a connected predicate between a 1st table having plural 1st fragments and a 2nd table having plural 2nd fragments and concerning the respective correspondent fragments from the 1st table, a retrieved connection fragment identifies a fragment from the 2nd table including a record satisfying the connected predicate with a record from a correspondent fragment from the 1st table. In order to delete the other fragments, a data base system generates or accesses a connection fragment map 36 in a data base 30. The connection fragment map 36 does not include any record indicating which fragment from two tables can satisfy the connected predicate but shows the unnecessity of retrieval during the execution of question and is used for deleting fragments which can not satisfy the connected predicate.

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