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公开(公告)号：US5905982A
公开(公告)日：1999-05-18
申请号：US835113
申请日：1997-04-04
IPC分类号： G06F17/30
CPC分类号： G06F17/30607 , Y10S707/955 , Y10S707/99932 , Y10S707/99933 , Y10S707/99934 , Y10S707/99935 , Y10S707/99953
摘要： A method, apparatus, and article of manufacture for handling NULL values in SQL queries over object oriented data. A two-phase method is used to enable a query evaluator in a two-valued logic environment to properly handle occurrences of NULL values for predicates that involve subqueries, i.e., basic subquery predicates and/or quantified subquery predicates. For basic subquery predicates, negation reduction is performed by applying logical equivalence rules and inverting basic comparators (e.g., transforming =) to eliminate NOTs. Then, transformations are employed for the resulting positive predicates to include NULL value testing, i.e., NULL protection. For quantified subquery predicates, in addition to performing negation reduction, quantified subqueries are converted into existential subqueries. In most cases, this yields a predicate that can be handled using NULL protection transformations for positive predicates. The exception (i.e., a "NOT EXISTS" resulting from the conversion step of a universally quantified subquery) is handled using NULL protection transformations for negative predicates. The evaluation of the NULL tested positive and negative predicates ensures that if a predicate has a NULL value, it is not included in the query result.
摘要翻译： 一种用于在面向对象数据的SQL查询中处理NULL值的方法，装置和制品。 两阶段方法用于使两值逻辑环境中的查询计算器正确地处理涉及子查询（即基本子查询谓词和/或量化子查询谓词）的谓词的NULL值的出现。 对于基本子查询谓词，通过应用逻辑等价规则和反转基本比较器（例如，转换
=）来消除NOT来执行否定减少。 然后，对所得到的积极谓词使用变换来包括NULL值测试，即NULL保护。 对于量化的子查询谓词，除了执行减法之外，量化的子查询也将转换为存在性子查询。 在大多数情况下，这产生了一个谓词，可以使用NULL保护转换来处理积极谓词。 使用针对负谓词的NULL保护转换来处理异常（即，由普遍量化的子查询的转换步骤产生的“NOT EXISTS”）。 NULL测试的正和负谓词的评估确保如果谓词具有NULL值，则不包括在查询结果中。 -
公开(公告)号：US06457020B1
公开(公告)日：2002-09-24
申请号：US09532179
申请日：2000-03-20
IPC分类号： G06F1730
CPC分类号： G06F17/30433 , Y10S707/955 , Y10S707/99944
摘要： A method, apparatus, and article of manufacture for a computer-implemented technique for query optimization using a multi-layered object cache. An object-oriented query is executed to retrieve data from a database. The database is stored on a data storage device connected to a computer and queries are run against lower cache layers which have better performance characteristics than the external or upper layers. The multi-layered cache has an application objects (AOs) cache and a data access objects (DAOs) cache, and the application objects include methods deriving data from DAOs. The method includes a step of rewriting the query into a query directed against the DAOs cache, applying a pushdown transformation algorithm to the rewritten query directed against the DAOs cache, and executing the transformed query against the DAOs cache. The method also allows optimizing queries with path expressions by transforming path expression into joins. Another performance optimization includes using a limited data set only including the inserted and updated data, which allows the method to evaluate queries against a subset of a collection of cached objects instead of an entire collection of cached objects.
摘要翻译： 一种用于使用多层对象缓存进行查询优化的计算机实现技术的方法，装置和制品。 执行面向对象的查询以从数据库检索数据。 数据库存储在连接到计算机的数据存储设备上，并且针对具有比外层或上层更好的性能特征的较低级缓存层运行查询。 多层缓存具有应用对象（AO）缓存和数据访问对象（DAO）缓存，并且应用对象包括从DAO导出数据的方法。 该方法包括将查询重写成针对DAO缓存的查询的步骤，将向下转换算法应用于针对DAO缓存的重写查询，以及针对DAO缓存执行转换查询。 该方法还允许通过将路径表达式转换为联接来优化具有路径表达式的查询。 另一个性能优化包括使用仅包括插入和更新的数据的有限数据集，其允许该方法针对缓存对象的集合的子集而不是整个高速缓存对象的集合来评估查询。
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公开(公告)号：US06285997B1
公开(公告)日：2001-09-04
申请号：US09192817
申请日：1998-11-16
IPC分类号： G06F1730
CPC分类号： G06F17/30457 , G06F17/30545 , Y10S707/955 , Y10S707/99932 , Y10S707/99934 , Y10S707/99938 , Y10S707/99944 , Y10S707/99945
摘要： A method, apparatus, and article of manufacture for a computer-implemented technique for query optimization with deferred updates and autonomous sources. An object-oriented query is executed to retrieve data from a database. The database is stored on a data storage device connected to a computer. The object-oriented query is transformed into subqueries, wherein at least one subquery is directed against a database, and wherein one subquery is directed against an object cache. Each subquery that is directed against a database is executed to retrieve data from the database into the object cache. The subquery that is directed against the object cache is executed to retrieve data for the query, wherein the data incorporates updates to the object cache and updates to the database.
摘要翻译： 用于具有延迟更新和自发源的用于查询优化的计算机实现技术的方法，装置和制品。 执行面向对象的查询以从数据库检索数据。 数据库存储在连接到计算机的数据存储设备上。 将面向对象的查询转换为子查询，其中至少一个子查询针对数据库，并且其中一个子查询针对对象高速缓存。 执行针对数据库的每个子查询，以将数据从数据库中检索到对象缓存中。 执行针对对象高速缓存的子查询以检索用于查询的数据，其中数据包含对对象缓存的更新和对数据库的更新。
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公开(公告)号：US06574639B2
公开(公告)日：2003-06-03
申请号：US09891453
申请日：2001-06-27
IPC分类号： G06F1730
CPC分类号： G06F17/30457 , G06F17/30545 , Y10S707/955 , Y10S707/99932 , Y10S707/99934 , Y10S707/99938 , Y10S707/99944 , Y10S707/99945
摘要： A method, apparatus, and article of manufacture for a computer-implemented technique for query optimization with deferred updates and autonomous sources. An object-oriented query is executed to retrieve data from a database. The database is stored on a data storage device connected to a computer. The object-oriented query is transformed into subqueries, wherein at least one subquery is directed against a database, and wherein one subquery is directed against an object cache. Each subquery that is directed against a database is executed to retrieve data from the database into the object cache. The subquery that is directed against the object cache is executed to retrieve data for the query, wherein the data incorporates updates to the object cache and updates to the database.
摘要翻译： 用于具有延迟更新和自发源的用于查询优化的计算机实现技术的方法，装置和制品。 执行面向对象的查询以从数据库检索数据。 数据库存储在连接到计算机的数据存储设备上。 将面向对象的查询转换为子查询，其中至少一个子查询针对数据库，并且其中一个子查询针对对象高速缓存。 执行针对数据库的每个子查询，以将数据从数据库中检索到对象缓存中。 执行针对对象高速缓存的子查询以检索用于查询的数据，其中数据包含对对象缓存的更新和对数据库的更新。
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公开(公告)号：US07107255B2
公开(公告)日：2006-09-12
申请号：US09887759
申请日：2001-06-21
IPC分类号： G06F17/30
CPC分类号： G06F17/30466 , Y10S707/99932 , Y10S707/99933 , Y10S707/99934 , Y10S707/99935
摘要： A query optimization technique that determines whether a query includes a self join that is transitively derived through table expressions having UNION operators. If so, the query is simplified to eliminate the table expressions and to reduce the query to an equivalent query over tables.
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公开(公告)号：US20050147240A1
公开(公告)日：2005-07-07
申请号：US10752154
申请日：2004-01-05
CPC分类号： G06F21/60 , G06F21/6227 , G06F21/6245
摘要： A system, method, and computer program product to automatically eliminate the distribution information available for reconstruction from a disguised dataset. The invention flattens input numerical values into a substantially uniformly distributed dataset, then maps the uniformly distributed dataset into equivalent data in a target distribution. The invention allows the incremental encryption of new values in an encrypted database while leaving existing encrypted values unchanged. The flattening comprises (1) partitioning, (2) mapping, and (3) saving auxiliary information about the data processing, which is encrypted and not updated. The partitioning is MDL based, and includes a growth phase for dividing a space into fine partitions and a prune phase for merging some partitions together.
摘要翻译： 一种系统，方法和计算机程序产品，用于自动从伪装的数据集中消除可用于重建的分发信息。 本发明将输入数值平坦化为基本上均匀分布的数据集，然后将均匀分布的数据集映射到目标分布中的等效数据。 本发明允许对加密数据库中的新值进行增量加密，同时保留现有加密值。 扁平化包括（1）划分，（2）映射和（3）保存关于被加密且未更新的数据处理的辅助信息。 分区是基于MDL，并且包括用于将空间分割成精细分区的生长阶段和用于将一些分区合并在一起的剪枝阶段。
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公开(公告)号：US06934712B2
公开(公告)日：2005-08-23
申请号：US09810167
申请日：2001-03-19
IPC分类号： G06F17/30
CPC分类号： G06F17/30917 , G06F17/30595 , G06F17/30932 , G06F17/30941 , Y10S707/99932 , Y10S707/99933 , Y10S707/99934 , Y10S707/99935 , Y10S707/99943
摘要： A method for publishing relational data as XML by translating XML queries into queries against a relational database. Conversion of the relational database into an XML database is not required. Each relational table is mapped to a virtual XML document, and XML queries are issued over these virtual documents. An XML query is parsed and transformed into a language-neutral intermediate representation, which is a sequence of operations describing how the output document is derived from the underlying relational tables. The intermediate representation is then translated into an SQL query over the underlying relational tables. The intermediate representation is also used to generate a tagger graph, which the tagger runtime ‘walks’ to generate the tagged, structured XML output. Each of the nodes of the tagger graph are operators which perform processing on the results of the SQL query. The SQL query is executed, and the SQL query results are then provided to the tagger. The tagger runtime applies the operators of each node to the inputs at that node to produce the structured XML document as a query result, guided by the structure of the tagger graph.
摘要翻译： 通过将XML查询转换为关系数据库的查询来将关系数据发布为XML的方法。 不需要将关系数据库转换为XML数据库。 每个关系表映射到一个虚拟XML文档，并通过这些虚拟文档发出XML查询。 解析XML查询并将其转换为语言中立的中间表示，它是描述输出文档如何从底层关系表导出的操作序列。 然后将中间表示形式转换为基础关系表中的SQL查询。 中间表示也用于生成标记图，标记运行时“走”来生成标记的结构化XML输出。 标记图中的每个节点都是对SQL查询结果执行处理的操作符。 执行SQL查询，然后将SQL查询结果提供给标记器。 标记运行时将每个节点的运算符应用于该节点的输入，以便通过标记器图的结构来指导结构化的XML文档作为查询结果。
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公开(公告)号：US06721730B2
公开(公告)日：2004-04-13
申请号：US09887582
申请日：2001-06-21
IPC分类号： G06F1730
CPC分类号： G06F17/30454 , Y10S707/99933 , Y10S707/99934
摘要： A query optimization technique that determines whether any column from a right quantifier of a left outer join query is projected out of the query. If not, then all predicates in an ON clause are removed from the left outer join query, the right quantifier is removed from the left outer join query, and the left outer join query is converted to a simple select query. A number of steps are performed to determine whether any of the columns quantified by the right quantifier participate in a projection list of the query. A set of equivalence class columns is computed for the query, wherein the equivalence classes are derived from equi-join predicates in the query. A set of columns quantified by the right quantifier across the computed set of equivalence classes is computed. A determination is made whether a subset of the set of columns form a key for the right quantifier. If the right quantifier columns are not projected out of the query, then the optimization may be performed.
摘要翻译： 一种查询优化技术，用于确定来自左侧外部连接查询的右侧定量器的任何列是否从该查询中投射出来。 如果没有，那么ON子句中的所有谓词将从左外连接查询中删除，右侧的量词会从左外连接查询中删除，左外连接查询将转换为简单的选择查询。 执行多个步骤以确定由右侧量词库量化的任何列是否参与查询的投影列表。 为查询计算一组等价类列，其中等价类是从查询中的等连接谓词导出的。 计算通过所计算的等价类集合的正确量词量化的一组列。 确定一组列的一个子集是否形成正确的量词的键。 如果正确的量词列不会从查询中投射出来，则可以执行优化。
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9.发明授权Database management system, method, and program for providing query rewrite transformations for nested set elimination in database views 失效数据库管理系统，方法和程序，用于为数据库视图中的嵌套集消除提供查询重写转换
公开(公告)号：US6006214A
公开(公告)日：1999-12-21
申请号：US760059
申请日：1996-12-04
IPC分类号： G06F17/30
CPC分类号： G06F17/30607 , G06F17/30471 , Y10S707/99932
摘要： The system, method, and program of this invention, referred to herein as nest elimination, performs query rewrite transformations, within a database management system (DBMS), for a certain class of object queries over views that involve derived nested sets. The nest elimination algorithm uses query rewriting to avoid computing these nested sets in certain common cases. For each quantifier in a query (if the quantifier is defined over a nested set that is a part of a view or if the quantifier is implemented by a subquery that projects a NEST aggregate) the following functions are performed: a) resetting an element to which a quantifier is bound in the database query to an argument of a nest aggregate function in a nest subquery of a view; b) adding a null testing predicate to the rewritten database query; c) adding quantifiers defined within the nest subquery to the rewritten database query; d) adding predicates from the nest subquery of the view to the rewritten database query; and e) rewriting each expression involving a quantifier over an instance into a path expression. The resulting rewritten query is then further processed by the DBMS such as through a query optimizer, etc. By avoiding nested set computations for a certain class of queries, the rewritten query can result in improved processing performance.
摘要翻译： 本发明的系统，方法和程序在本文中被称为嵌套消除，在数据库管理系统（DBMS）内对涉及派生嵌套集的视图的某一类对象查询执行查询重写转换。 巢消除算法使用查询重写以避免在某些常见情况下计算这些嵌套集。 对于查询中的每个量词（如果量词是在作为视图的一部分的嵌套集中定义的，或者如果量词是由投影NEST聚合的子查询实现的）执行以下功能：a）将元素重置为 数据库查询中的量词在视图的嵌套子查询中嵌套到巢集合函数的参数; b）向重写的数据库查询中添加一个空测试谓词; c）将嵌套子查询中定义的量词添加到重写的数据库查询中; d）将视图的嵌套子查询中的谓词添加到重写的数据库查询中; 以及e）将涉及实例上的量词的每个表达重写为路径表达式。 所得到的重写查询然后由DBMS进一步处理，例如通过查询优化器等。通过避免某些类别的查询的嵌套集计算，重写的查询可以导致改进的处理性能。
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公开(公告)号：US07752446B2
公开(公告)日：2010-07-06
申请号：US10147741
申请日：2002-05-15
IPC分类号： H04L9/32
CPC分类号： G06F21/10 , G06F21/6227 , G06F2221/0737
摘要： A method and system for enhancing security in a database by establishing a bit pattern using secret information, the pattern establishing a watermark that can be detected in a copy (authorized or not) of the database only by using the secret information.
摘要翻译： 一种用于通过使用秘密信息建立比特模式来增强数据库中的安全性的方法和系统，所述模式仅通过使用秘密信息来建立可以在数据库（授权或不授权）的副本中被检测到的水印。
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