Accelerating value-based lookup of XML document in XQuery
    1.
    发明授权
    Accelerating value-based lookup of XML document in XQuery 有权
    在XQuery中加速基于价值的XML文档查找

    公开(公告)号:US07836098B2

    公开(公告)日:2010-11-16

    申请号:US11827801

    申请日:2007-07-13

    IPC分类号: G06F7/00 G06F17/30

    CPC分类号: G06F17/30938

    摘要: A method and apparatus for accelerating value-based lookups of XML documents in XQuery is provided. XML indices can help to optimize SQL queries of XML documents stored in object-relational databases. Certain SQL/XML functions such as XMLTABLE( ) use XQuery expressions to query XML documents. Previously, such queries could not use the XML index because the PATH table of the XML index was not defined for XQuery semantics. Techniques described herein extend the XML index for use with queries that require evaluation of XQuery expressions. Consequently, techniques described herein accelerate value-based lookups of XML documents in XQuery by introducing the possibility of an index-assisted evaluation of XQuery expressions.

    摘要翻译: 提供了一种用于在XQuery中加速基于价值的XML文档查找的方法和装置。 XML索引可以帮助优化存储在对象关系数据库中的XML文档的SQL查询。 某些SQL / XML函数(如XMLTABLE())使用XQuery表达式来查询XML文档。 以前,这样的查询无法使用XML索引,因为XML索引的PATH表未针对XQuery语义进行定义。 本文中描述的技术扩展了XML索引,以便与需要评估XQuery表达式的查询一起使用。 因此,本文描述的技术通过引入XQuery表达式的索引辅助评估的可能性来加速XQuery中的XML文档的基于值的查找。

    Using sibling-count in XML indexes to optimize single-path queries
    2.
    发明授权
    Using sibling-count in XML indexes to optimize single-path queries 有权
    在XML索引中使用sibling-count来优化单路径查询

    公开(公告)号:US07840609B2

    公开(公告)日:2010-11-23

    申请号:US11888415

    申请日:2007-07-31

    IPC分类号: G06F7/00

    CPC分类号: G06F17/30935 G06F17/30442

    摘要: A method and apparatus are provided for using sibling-counts in XML indices to optimize single-path queries. Using a b-tree XML index with a SQL query logarithmically reduces the number of disk accesses by passing over index entries where it is determined that a match will not be found. However, because certain index entries are passed over, it is impossible to ascertain if a path expression occurs more than once in the XML index, as certain queries sometimes require. This hurdle can be overcome by maintaining a sibling count with each node entry in the XML index. Because the sibling count is stored with the index entry, the index will reveal whether the matching node is single or has other siblings. In additional to re-writing the original query for optimization by use of an XML index, it will be re-written to check for a single-path condition in the index.

    摘要翻译: 提供了一种方法和装置,用于在XML索引中使用同级计数来优化单路径查询。 在SQL查询中使用b-tree XML索引对数地减少了通过传递索引条目的磁盘访问次数,确定不会找到匹配项。 但是,由于某些索引条目被传递,因此某些查询有时需要,无法确定路径表达式是否在XML索引中多次出现。 通过维护XML索引中每个节点条目的兄弟数量,可以克服这个障碍。 由于兄弟计数与索引条目一起存储,索引将显示匹配节点是单个节点还是具有其他兄弟节点。 除了通过使用XML索引重新编写原始查询进行优化外,还将重新编写索引中的单路径条件。

    Combining Streaming And Navigation For Evaluating XML Queries
    3.
    发明申请
    Combining Streaming And Navigation For Evaluating XML Queries 有权
    结合流和导航来评估XML查询

    公开(公告)号:US20090125480A1

    公开(公告)日:2009-05-14

    申请号:US11937357

    申请日:2007-11-08

    IPC分类号: G06F17/30

    CPC分类号: G06F17/30932 G06F17/30935

    摘要: A query is rewritten to combine streaming evaluation and XML index evaluation. The query is rewritten to include a streaming operator (e.g. function) that, when executed, uses streaming evaluation. Further, the query is rewritten so that XML index evaluation of a path expression also produces location information that identifies the location of a node within an XML document. The streaming operator is able to exploit the location information to begin and end scanning rather than scanning the entire XML document.

    摘要翻译: 重写查询以组合流评估和XML索引评估。 该查询被重写以包括流执行器(例如,功能),当被执行时,使用流评估。 此外,重写该查询,使得路径表达式的XML索引评估还产生标识XML文档中的节点的位置的位置信息。 流操作员能够利用位置信息开始和结束扫描,而不是扫描整个XML文档。

    Using sibling-count in XML indexes to optimize single-path queries
    4.
    发明申请
    Using sibling-count in XML indexes to optimize single-path queries 有权
    在XML索引中使用sibling-count来优化单路径查询

    公开(公告)号:US20090037369A1

    公开(公告)日:2009-02-05

    申请号:US11888415

    申请日:2007-07-31

    IPC分类号: G06F17/30

    CPC分类号: G06F17/30935 G06F17/30442

    摘要: A method and apparatus are provided for using sibling-counts in XML indices to optimize single-path queries. Using a b-tree XML index with a SQL query logarithmically reduces the number of disk accesses by passing over index entries where it is determined that a match will not be found. However, because certain index entries are passed over, it is impossible to ascertain if a path expression occurs more than once in the XML index, as certain queries sometimes require. This hurdle can be overcome by maintaining a sibling count with each node entry in the XML index. Because the sibling count is stored with the index entry, the index will reveal whether the matching node is single or has other siblings. In additional to re-writing the original query for optimization by use of an XML index, it will be re-written to check for a single-path condition in the index.

    摘要翻译: 提供了一种方法和装置,用于在XML索引中使用同级计数来优化单路径查询。 在SQL查询中使用b-tree XML索引对数地减少了通过传递索引条目的磁盘访问次数,确定不会找到匹配项。 但是,由于某些索引条目被传递,因此某些查询有时需要,无法确定路径表达式是否在XML索引中多次出现。 通过维护XML索引中每个节点条目的兄弟数量,可以克服这个障碍。 由于兄弟计数与索引条目一起存储,索引将显示匹配节点是单个节点还是具有其他兄弟节点。 除了通过使用XML索引重新编写原始查询进行优化外,还将重新编写索引中的单路径条件。

    Accessing data from asynchronously maintained index
    5.
    发明授权
    Accessing data from asynchronously maintained index 有权
    从异步维护的索引访问数据

    公开(公告)号:US07814117B2

    公开(公告)日:2010-10-12

    申请号:US11784341

    申请日:2007-04-05

    IPC分类号: G06F7/00 G06F17/30

    摘要: A method and apparatus for computing queries in a way that is consistent with an index and the underlying base table is provided. A query is computed such that it is consistent with the state of an index and base table as of the last point at which the index and table were synchronized. For example, if an index is maintained asynchronously then it is not necessarily consistent with its base table when a query is to be run against the table and the index. Therefore, the query is computed such that it will be consistent with the last point at which the index and the table were synchronized. In one embodiment, a System Change Number (SCN) of the last successful synchronization operation is used to perform a flashback query on the table.

    摘要翻译: 提供了一种以与索引和底层基表一致的方式计算查询的方法和装置。 计算一个查询,使得它与索引和基表的状态一致,该索引和基表与索引和表同步的最后一个点相同。 例如,如果异步维护索引,则当要对表和索引运行查询时,它不一定与其基表一致。 因此,计算查询使其与索引和表同步的最后一个点一致。 在一个实施例中,使用上一次成功同步操作的系统更改编号(SCN)来对表执行闪回查询。

    Technique For Using Occurrence Constraints To Optimize XML Index Access
    6.
    发明申请
    Technique For Using Occurrence Constraints To Optimize XML Index Access 审中-公开
    使用发生约束优化XML索引访问的技术

    公开(公告)号:US20100030727A1

    公开(公告)日:2010-02-04

    申请号:US12181745

    申请日:2008-07-29

    IPC分类号: G06F7/00 G06F17/30

    CPC分类号: G06F16/81 G06F16/8365

    摘要: Approaches are provided for improving the performance of certain database queries that operate on binary-encoded XML. In particular, the approach uses occurrence and type constraint information about XML data stored in the database for optimizing the relational rewrite of a query. Constraint information can be obtained in several different ways including through a formal language specification such as an XML Schema or DTD, through discovery of a user-provided secondary index on a an XML path table, or through a structural summary that is derived from statistical analysis on a set of XML documents stored in the database.

    摘要翻译: 提供了一些方法来提高对二进制编码的XML进行操作的某些数据库查询的性能。 特别地,该方法使用关于存储在数据库中的XML数据的出现和类型约束信息来优化查询的关系重写。 约束信息可以通过几种不同的方式获得,包括通过诸如XML模式或DTD的形式语言规范,通过在XML路径表上发现用户提供的辅助索引,或通过从统计分析得出的结构性摘要来获得约束信息 在一组存储在数据库中的XML文档中。

    Combining streaming and navigation for evaluating XML queries
    9.
    发明授权
    Combining streaming and navigation for evaluating XML queries 有权
    结合流和导航来评估XML查询

    公开(公告)号:US08180791B2

    公开(公告)日:2012-05-15

    申请号:US11937357

    申请日:2007-11-08

    IPC分类号: G06F7/00

    CPC分类号: G06F17/30932 G06F17/30935

    摘要: A query is rewritten to combine streaming evaluation and XML index evaluation. The query is rewritten to include a streaming operator (e.g. function) that, when executed, uses streaming evaluation. Further, the query is rewritten so that XML index evaluation of a path expression also produces location information that identifies the location of a node within an XML document. The streaming operator is able to exploit the location information to begin and end scanning rather than scanning the entire XML document.

    摘要翻译: 重写查询以组合流评估和XML索引评估。 该查询被重写以包括流执行器(例如,功能),当被执行时,使用流评估。 此外,重写该查询,使得路径表达式的XML索引评估还产生标识XML文档中的节点的位置的位置信息。 流操作员能够利用位置信息开始和结束扫描,而不是扫描整个XML文档。

    Global query normalization to improve XML index based rewrites for path subsetted index
    10.
    发明授权
    Global query normalization to improve XML index based rewrites for path subsetted index 有权
    全局查询规范化,以改进路径子集索引的基于XML索引的重写

    公开(公告)号:US07991768B2

    公开(公告)日:2011-08-02

    申请号:US11937268

    申请日:2007-11-08

    IPC分类号: G06F7/00 G06F17/30

    CPC分类号: G06F17/30911 G06F17/30935

    摘要: Techniques for processing a query that includes a path expression are provided. A query processor determines whether an XML index may be used to execute the query instead of having to scan multiple XML documents. The query is parsed and normalized, which results in multiple normalized path expressions that are based on the original path expression. If the XML index is a path-subsetted index, then the query processor generates annotated path expressions based on the normalized path expressions. The query processor determines whether each of the annotated path expressions is satisfiable by the path-subsetted XML index. If so, then the XML index is used to process the query.

    摘要翻译: 提供了处理包含路径表达式的查询的技术。 查询处理器确定是否可以使用XML索引来执行查询,而不必扫描多个XML文档。 查询被解析和归一化,这导致基于原始路径表达式的多个标准化路径表达式。 如果XML索引是路径子集索引,则查询处理器将根据归一化的路径表达式生成带注释的路径表达式。 查询处理器确定每个注释路径表达式是否由路径子集的XML索引满足。 如果是这样,则使用XML索引来处理查询。