-
1.发明申请公开(公告)号：US20080154846A1
公开(公告)日：2008-06-26
申请号：US12042065
申请日：2008-03-04
IPC分类号： G06F17/30
CPC分类号： G06F17/30469 , Y10S707/99931 , Y10S707/99932 , Y10S707/99933 , Y10S707/99934 , Y10S707/99935
摘要： A method for consistent selectivity estimation based on the principle of maximum entropy (ME) is provided. The method efficiently exploits all available information and avoids the bias problem. In the absence of detailed knowledge, the ME approach reduces to standard uniformity and independence assumptions. The disclosed method, based on the principle of ME, is used to improve the optimizer's cardinality estimates by orders of magnitude, resulting in better plan quality and significantly reduced query execution times.
摘要翻译： 提供了一种基于最大熵原理（ME）的一致选择性估计方法。 该方法有效地利用了所有可用信息，避免了偏差问题。 在没有详细知识的情况下，ME方法减少到标准统一性和独立性假设。 所公开的方法，基于ME的原理，用于提高优化器的基数估计数量级，导致更好的计划质量和显着减少的查询执行时间。
-
2.发明授权Selectivity estimation for conjunctive predicates in the presence of partial knowledge about multivariate data distributions 失效在有关多变量数据分布的部分知识的情况下，联合谓词的选择性估计公开(公告)号：US08135701B2
公开(公告)日：2012-03-13
申请号：US12042065
申请日：2008-03-04
IPC分类号： G06F7/00
CPC分类号： G06F17/30469 , Y10S707/99931 , Y10S707/99932 , Y10S707/99933 , Y10S707/99934 , Y10S707/99935
摘要： A method for consistent selectivity estimation based on the principle of maximum entropy (ME) is provided. The method efficiently exploits all available information and avoids the bias problem. In the absence of detailed knowledge, the ME approach reduces to standard uniformity and independence assumptions. The disclosed method, based on the principle of ME, is used to improve the optimizer's cardinality estimates by orders of magnitude, resulting in better plan quality and significantly reduced query execution times.
摘要翻译： 提供了一种基于最大熵原理（ME）的一致选择性估计方法。 该方法有效地利用了所有可用信息，避免了偏差问题。 在没有详细知识的情况下，ME方法减少到标准统一性和独立性假设。 所公开的方法，基于ME的原理，用于提高优化器的基数估计数量级，导致更好的计划质量和显着减少的查询执行时间。
-
3.发明授权Selectivity estimation for conjunctive predicates in the presence of partial knowledge about multivariate data distributions 失效在有关多变量数据分布的部分知识的情况下，联合谓词的选择性估计公开(公告)号：US07376639B2
公开(公告)日：2008-05-20
申请号：US11190947
申请日：2005-07-28
CPC分类号： G06F17/30469 , Y10S707/99931 , Y10S707/99932 , Y10S707/99933 , Y10S707/99934 , Y10S707/99935
摘要： A method for consistent selectivity estimation based on the principle of maximum entropy (ME) is provided. The method efficiently exploits all available information and avoids the bias problem. In the absence of detailed knowledge, the ME approach reduces to standard uniformity and independence assumptions. The disclosed method, based on the principle of ME, is used to improve the optimizer's cardinality estimates by orders of magnitude, resulting in better plan quality and significantly reduced query execution times.
摘要翻译： 提供了一种基于最大熵原理（ME）的一致选择性估计方法。 该方法有效地利用了所有可用信息，避免了偏差问题。 在没有详细知识的情况下，ME方法减少到标准统一性和独立性假设。 所公开的方法，基于ME的原理，用于提高优化器的基数估计数量级，导致更好的计划质量和显着减少的查询执行时间。
-
公开(公告)号：US08051058B2
公开(公告)日：2011-11-01
申请号：US12209382
申请日：2008-09-12
IPC分类号： G06F17/30
CPC分类号： G06F17/30469 , Y10S707/99931 , Y10S707/99932 , Y10S707/99933 , Y10S707/99934 , Y10S707/99935
摘要： A system for estimating cardinalities for a plurality of columns in a database system is disclosed. The system include obtaining statistics collected for the plurality of columns. A first portion of the statistics indicates at least one relationship between at least a portion of the plurality of columns, while a second portion of the statistics includes single column statistics. The system also include utilizing the first portion and the second portion of the statistics to estimate the cardinality for the plurality of columns.
摘要翻译： 公开了一种用于估计数据库系统中的多个列的基数的系统。 系统包括获取针对多个列收集的统计信息。 统计的第一部分指示多个列的至少一部分之间的至少一个关系，而统计的第二部分包括单列统计。 该系统还包括利用统计的第一部分和第二部分来估计多个列的基数。
-
5.发明授权Optimization of extensible markup language path language (XPATH) expressions in a database management system configured to accept extensible markup language (XML) queries 有权配置为接受可扩展标记语言（XML）查询的数据库管理系统中的可扩展标记语言路径语言（XPATH）表达式的优化公开(公告)号：US07865502B2
公开(公告)日：2011-01-04
申请号：US12101141
申请日：2008-04-10
申请人： Andrey Balmin , Fatma Ozcan , Tam Minh Dai Tran
发明人： Andrey Balmin , Fatma Ozcan , Tam Minh Dai Tran
IPC分类号： G06F7/00
CPC分类号： G06F17/30923
摘要： An apparatus, system, and method are disclosed for optimization of XPath expressions in a database management system configured to accept XML queries. Operations of the method include receiving an XQuery representation and partitioning XPath expressions within the XQuery representation into a plurality of XPath expression clusters. The XPath expression clusters may comprise one or more XPath expressions and those in each cluster may operate on a common document. Furthermore, the XPath expressions in each cluster are hierarchically related to each other such that branch nodes of the cluster are executable independent of nodes in other XPath expression clusters. The method also defines merging the one or more XPath expressions into one or more expression trees for each XPath expression cluster. The method generates one or more query execution plans from the one or more XPath expression blocks. The method includes, for each query execution plan, splitting each of the XPath expression blocks into one or more ordered fragments. The method determines a cardinality according to database statistics and an execution cost for each XPath expression block within each query execution plan. Finally, the method determines an aggregate cardinality for each query execution plan and an aggregate execution cost for each query execution plan. Therefore, an XQuery may be optimized at both the global XQuery and local XPath expression block level, improving performance and reducing overhead.
摘要翻译： 公开了一种用于在被配置为接受XML查询的数据库管理系统中优化XPath表达式的装置，系统和方法。 该方法的操作包括接收XQuery表示并将XQuery表示内的XPath表达式分解成多个XPath表达式集群。 XPath表达式集群可以包括一个或多个XPath表达式，并且每个集群中的那些可以在公共文档上操作。 此外，每个集群中的XPath表达式彼此分层相关，使得集群的分支节点可执行为独立于其他XPath表达式集群中的节点。 该方法还定义将一个或多个XPath表达式合并到每个XPath表达式集群的一个或多个表达式树中。 该方法从一个或多个XPath表达式块生成一个或多个查询执行计划。 对于每个查询执行计划，该方法包括将每个XPath表达块分解成一个或多个有序的片段。 该方法根据数据库统计信息确定基数，并确定每个查询执行计划中每个XPath表达式块的执行成本。 最后，该方法确定每个查询执行计划的聚合基数以及每个查询执行计划的总执行成本。 因此，可以在全局XQuery和本地XPath表达式块级别优化XQuery，从而提高性能并减少开销。
-
公开(公告)号：US20130173528A1
公开(公告)日：2013-07-04
申请号：US13340288
申请日：2011-12-29
IPC分类号： G06F17/30
CPC分类号： G06F17/30451
摘要： Techniques are described for optimizing a multi-fact star schema query to retrieve data from two or more fact tables of a database. The optimization techniques may include internally transforming a received multi-fact star schema query into a group of single-fact sub-queries, thereby reducing or eliminating certain constraints during query processing. The group of sub-queries may be enumerated to determine a query execution plan. The multi-fact star schema query may be executed according to the query execution plan to retrieve the data from the two or more fact tables of the database.
摘要翻译： 描述了用于优化多事实星型模式查询以从数据库的两个或多个事实表检索数据的技术。 优化技术可以包括将所接收的多事实星型模式查询内部变换成一组单事实子查询，从而在查询处理期间减少或消除某些约束。 可以枚举一组子查询来确定查询执行计划。 可以根据查询执行计划来执行多事实星型模式查询，以从数据库的两个或更多个事实表中检索数据。
-
公开(公告)号：US07478083B2
公开(公告)日：2009-01-13
申请号：US11278532
申请日：2006-04-03
CPC分类号： G06F17/30469 , Y10S707/99931 , Y10S707/99932 , Y10S707/99933 , Y10S707/99934 , Y10S707/99935
摘要： A method and system for estimating cardinalities for a plurality of columns in a database system is disclosed. The method and system include obtaining statistics collected for the plurality of columns. A first portion of the statistics indicates at least one relationship between at least a portion of the plurality of columns, while a second portion of the statistics includes single column statistics. The method and system also include utilizing the first portion and the second portion of the statistics to estimate the cardinality for the plurality of columns.
摘要翻译： 公开了一种用于估计数据库系统中的多个列的基数的方法和系统。 所述方法和系统包括获得针对所述多个列收集的统计信息。 统计的第一部分指示多个列中的至少一部分之间的至少一个关系，而统计的第二部分包括单列统计。 方法和系统还包括利用统计的第一部分和第二部分来估计多个列的基数。
-
公开(公告)号：US08589382B2
公开(公告)日：2013-11-19
申请号：US13340288
申请日：2011-12-29
IPC分类号： G06F17/30
CPC分类号： G06F17/30451
摘要： Techniques are described for optimizing a multi-fact star schema query to retrieve data from two or more fact tables of a database. The optimization techniques may include internally transforming a received multi-fact star schema query into a group of single-fact sub-queries, thereby reducing or eliminating certain constraints during query processing. The group of sub-queries may be enumerated to determine a query execution plan. The multi-fact star schema query may be executed according to the query execution plan to retrieve the data from the two or more fact tables of the database.
摘要翻译： 描述了用于优化多事实星型模式查询以从数据库的两个或多个事实表检索数据的技术。 优化技术可以包括将接收到的多事实星型模式查询内部变换成一组单事实子查询，从而在查询处理期间减少或消除某些约束。 可以枚举一组子查询来确定查询执行计划。 可以根据查询执行计划执行多事实星型模式查询，以从数据库的两个或更多个事实表中检索数据。
-
-
-
-
-
-
-
搜索结果
8 条记录 (耗时 0.019 秒)