Null aware anti-join
    1.
    发明授权
    Null aware anti-join 有权
    无意识反加入

    公开(公告)号:US07676450B2

    公开(公告)日:2010-03-09

    申请号:US11716462

    申请日:2007-03-08

    IPC分类号: G06F17/30

    摘要: Techniques for performing a “null-aware” anti-join operation are described. Unnesting using anti-join of NOT IN/ALL subquery uses null-aware anti-join operation, resulting in a rewritten query that, when computed, produces results consistent with the NULL semantics of NOT IN/ALL subquery. The semantics of the “null-aware” anti-join operation allow the query having the NOT IN/ALL subquery to be rewritten even though a no-NULL restriction requirement, for the operands of the anti-join condition in the query, may not be met.

    摘要翻译: 描述了执行“零感知”反连接操作的技术。 使用NOT IN / ALL子查询的反连接进行Unnesting使用了空感知反连接操作,导致重写的查询在计算时产生与NOT IN / ALL子查询的NULL语义一致的结果。 “空感知”反连接操作的语义允许具有NOT IN / ALL子查询的查询被重写,即使对于查询中的反连接条件的操作数的no-NULL限制要求也不可能 满足。

    Finding the TOP N values through the execution of a query
    2.
    发明授权
    Finding the TOP N values through the execution of a query 有权
    通过执行查询查找TOP N值

    公开(公告)号:US06546382B1

    公开(公告)日:2003-04-08

    申请号:US09433827

    申请日:1999-11-03

    IPC分类号: G06F1730

    摘要: A method and mechanism is provided for executing a query that includes a subquery, where the subquery includes an ORDER BY clause. The results generated by executing the subquery are ordered as specified by the ORDER BY clause. When the results of the subquery are referenced by the outer query, the results generated for the subquery satisfy the restriction. For example, the restriction may specify that the row number pseudo-column be less than a threshold. In response, a TOP N operation is performed to return the rows that are TOP N in order. The order is based on the ORDER BY clause.

    摘要翻译: 提供了一种方法和机制,用于执行包含子查询的查询,其中子查询包含ORDER BY子句。 通过执行子查询生成的结果按照ORDER BY子句的指定进行排序。 当子查询的结果由外部查询引用时,为子查询生成的结果满足限制。 例如,限制可以指定行号伪列小于阈值。 作为响应,执行TOP N操作以依次返回TOP N的行。 该订单基于ORDER BY子句。

    Null aware anti-join
    3.
    发明申请
    Null aware anti-join 有权
    无意识反加入

    公开(公告)号:US20070219952A1

    公开(公告)日:2007-09-20

    申请号:US11716462

    申请日:2007-03-08

    IPC分类号: G06F17/30

    摘要: Unnesting using anti-join of NOT IN/ALL subquery uses null-aware anti-join operation, resulting in a rewritten query that, when computed, produces results consistent with the NULL semantics of NOT IN/ALL subquery.

    摘要翻译: 使用NOT IN / ALL子查询的反连接进行Unnesting使用了空感知反连接操作,导致重写的查询在计算时产生与NOT IN / ALL子查询的NULL语义一致的结果。

    Using global temporary tables to transform queries
    4.
    发明授权
    Using global temporary tables to transform queries 有权
    使用全局临时表来转换查询

    公开(公告)号:US06684203B1

    公开(公告)日:2004-01-27

    申请号:US09436053

    申请日:1999-11-08

    IPC分类号: G06F1730

    摘要: A technique and mechanism for transforming a query is described. A given query is transformed into a transformed query that references a global temporary table. Specifically, the given query contains a join between a given table and one or more other tables referenced by constraints (e.g. predicates). References to one or more of the constrained tables are replaced by a reference to a global temporary table. Before executing the transformed query, data that satisfies the constraints placed on the constrained table is inserted into the global temporary table.

    摘要翻译: 描述了用于转换查询的技术和机制。 给定的查询被转换为引用全局临时表的转换查询。 具体来说,给定的查询包含一个给定表和一个或多个由约束引用的其他表(例如谓词)之间的连接。 对一个或多个受约束的引用由对全局临时表的引用替代。 在执行转换查询之前,将满足约束表上约束的数据插入到全局临时表中。