公开(公告)号：US20060036576A1

公开(公告)日：2006-02-16

申请号：US11256440

申请日：2005-10-21

Applicant: David Simmen

Inventor： David Simmen

IPC: G06F17/30

CPC classification number: G06F17/30463

Abstract: Data in materialized query tables (MQTs) are used as statistics for determining the optimal execution plan for a query. When an MQT is defined, it is examined to determine whether its data provides statistics for determining an optimal execution plan for a query. If so, then the MQT is identified, in the RDBMS, as a source for statistics. Information needed to exploit the MQT data as statistics is cataloged in the RDBMS. This information includes a characterization of the type of statistics provided by the MQT, the table and column distributions represented by those statistics, and a query for later retrieving relevant data from the MQT during the query optimization process. When a query is accepted for execution, the cataloged relevant information about MQTs is examined to determine whether an MQT exists that provides statistics relevant to optimization of the query. If such an MQT exists, then the relevant data is retrieved from the MQT using the cataloged query. Using the retrieved statistics, an optimal execution plan may be determined for the query.

Abstract translation: 物化查询表（MQT）中的数据用作确定查询的最佳执行计划的统计信息。 当定义MQT时，将对其进行检查以确定其数据是否提供用于确定查询的最佳执行计划的统计信息。 如果是这样，则在RDBMS中将MQT标识为统计信息源。 在RDBMS中编制统计数据来利用MQT数据所需的信息。 该信息包括由MQT提供的统计信息类型的表征，由这些统计信息表示的表和列分布以及用于稍后在查询优化过程中从MQT检索相关数据的查询。 当查询被接受执行时，将检查有关MQT的编目相关信息，以确定是否存在提供与查询优化相关的统计信息的MQT。 如果存在这样的MQT，则使用编目查询从MQT检索相关数据。 使用检索的统计信息，可以为查询确定最佳执行计划。

公开(公告)号：US09558251B2

公开(公告)日：2017-01-31

申请号：US13478284

申请日：2012-05-23

Applicant: David Simmen ,  Shant Hovsepian ,  Jeffrey Davis

Inventor： David Simmen ,  Shant Hovsepian ,  Jeffrey Davis

IPC: G06F17/30 ,  H03M7/30

CPC classification number: G06F17/30569 ,  G06F17/30283 ,  G06F17/30312 ,  H03M7/30 ,  H03M7/70 ,  H03M7/702

Abstract: One or more transformation functions can be used in connection or together with one or more compression/decompression techniques. A transformation function can transform data (e.g., a data object) into a form more suitable for compression and/or decompression. As a result, data can be compressed and/or decompressed more effectively. In addition, multiple data objects can be associated with various transformation functions and/or compression/decompression techniques. As a result, different approaches can be taken with respect to compression and decompression of data objects in an effort to find an optimum approach for compression of data objects that may vary significantly from each other and change over time. It will be appreciated that the objects can be associated with transformation functions in a dynamic manner to accommodate changes to data. Also, an extendible and/or extensible system can allow for growth and adaption of new data in forms not currently present or expected.

Abstract translation: 一个或多个变换函数可以连接使用或与一个或多个压缩/解压缩技术一起使用。 转换函数可以将数据（例如，数据对象）转换为更适合于压缩和/或解压缩的形式。 因此，可以更有效地压缩和/或解压缩数据。 此外，多个数据对象可以与各种变换函数和/或压缩/解压缩技术相关联。 因此，可以针对数据对象的压缩和解压缩采取不同的方法，努力找到可能彼此显着变化并随时间变化的数据对象的压缩的最佳方法。 应当理解，对象可以以动态方式与变换函数相关联以适应数据的改变。 此外，可扩展和/或可扩展的系统可以允许以当前不存在或预期的形式增加和适应新数据。

公开(公告)号：US20070214104A1

公开(公告)日：2007-09-13

申请号：US11369394

申请日：2006-03-07

Applicant: Bingjie Miao ,  David Simmen

Inventor： Bingjie Miao ,  David Simmen

IPC: G06F17/30

CPC classification number: G06F16/24542

Abstract: A method and system are provided for optimizing a query migrated from a source database system to a possibly dissimilar target database system, wherein the execution plan chosen for the migrated query is communicated from the source database system. Explain facilities of the source database system are used to gather information describing the execution plan used in the source database system for the migrated query. The explain information is then used to obtain plan directives for communicating the execution plan to the optimizer of the target system. If the obtained plan directives require auxiliary data structures, the source system catalogs are queried to determine the attributes of these auxiliary structures. These attributes are then used to create equivalent auxiliary structures in the target system. The migrated query is then optimized using the obtained plan directives, thus enabling database migration to preserve the investment made in tuning the execution plan on the source system

Abstract translation: 提供了一种方法和系统，用于优化从源数据库系统迁移到可能不相似的目标数据库系统的查询，其中为源迁移查询选择的执行计划从源数据库系统传送。 源数据库系统的解释设施用于收集描述迁移查询的源数据库系统中使用的执行计划的信息。 然后使用说明信息来获取用于将执行计划传送到目标系统的优化器的计划指令。 如果获得的计划指令需要辅助数据结构，则会查询源系统目录以确定这些辅助结构的属性。 然后，这些属性用于在目标系统中创建等效的辅助结构。 然后，使用获取的计划指令优化迁移的查询，从而实现数据库迁移，以保留对源系统调整执行计划的投资

公开(公告)号：US20130262408A1

公开(公告)日：2013-10-03

申请号：US13478284

申请日：2012-05-23

Applicant: David Simmen ,  Shant Hovsepian ,  Jeffrey Davis

Inventor： David Simmen ,  Shant Hovsepian ,  Jeffrey Davis

IPC: G06F17/30

CPC classification number: G06F17/30569 ,  G06F17/30283 ,  G06F17/30312 ,  H03M7/30 ,  H03M7/70 ,  H03M7/702

Abstract: One or more transformation functions can be used in connection or together with one or more compression/decompression techniques. A transformation function can transform data (e.g., a data object) into a form more suitable for compression and/or decompression. As a result, data can be compressed and/or decompressed more effectively. In addition, multiple data objects can be associated with various transformation functions and/or compression/decompression techniques. As a result, different approaches can be taken with respect to compression and decompression of data objects in an effort to find an optimum approach for compression of data objects that may vary significantly from each other and change over time. It will be appreciated that the objects can be associated with transformation functions in a dynamic manner to accommodate changes to data. Also, an extendible and/or extensible system can allow for growth and adaption of new data in forms not currently present or expected.

Abstract translation: 一个或多个变换函数可以连接使用或与一个或多个压缩/解压缩技术一起使用。 转换函数可以将数据（例如，数据对象）转换为更适合于压缩和/或解压缩的形式。 因此，可以更有效地压缩和/或解压缩数据。 此外，多个数据对象可以与各种变换函数和/或压缩/解压缩技术相关联。 因此，可以针对数据对象的压缩和解压缩采取不同的方法，努力找到可能彼此显着变化并随时间变化的数据对象的压缩的最佳方法。 应当理解，对象可以以动态方式与变换函数相关联以适应数据的改变。 此外，可扩展和/或可扩展的系统可以允许以当前不存在或预期的形式增加和适应新数据。

公开(公告)号：US20070162425A1

公开(公告)日：2007-07-12

申请号：US11327125

申请日：2006-01-06

Applicant: Anjali Betawadkar-Norwood ,  Susanne Englert ,  Simon Harris ,  David Simmen ,  Hansjorg Zeller

Inventor： Anjali Betawadkar-Norwood ,  Susanne Englert ,  Simon Harris ,  David Simmen ,  Hansjorg Zeller

IPC: G06F17/30

CPC classification number: G06F16/24535

Abstract: Method, apparatus and computer usable medium tangibly embodying a program of instructions is provided for performing advanced cost/benefit analysis of subplans of a query execution plan, in a computer system having a database software server. Method augments a cost estimation model, obtained from an optimizer of the software server after determination of an optimal query execution plan, with a cost/benefit analysis of operating each subplan of the query execution plan asynchronously. It calculates a subplan elapsed time benefit of making the subplan asynchronous using a set of cost estimates for each subplan operation and knowledge of the execution sequence of the query execution plan operations, all provided by the query optimizer. Set of subplans for asynchronous execution is chosen to form an optimal set of subplans while respecting a resource constraint, for providing a maximal reduction of the total query elapsed time while conserving system resources of the software server.

Abstract translation: 提供了有形地体现指令程序的方法，装置和计算机可用介质，用于在具有数据库软件服务器的计算机系统中执行查询执行计划的子计划的高级成本/效益分析。 方法增加了在确定最佳查询执行计划之后从软件服务器的优化器获得的成本估计模型，并以异步方式操作查询执行计划的每个子计划的成本/效益分析。 它使用查询优化器提供的每个子计划操作的一组成本估计和查询执行计划操作的执行顺序的知识来计算使子计划异步的子计划经过时间的好处。 选择用于异步执行的子计划的集合，以在遵守资源约束的情况下形成最佳的子计划集合，以在节省软件服务器的系统资源的同时提供总查询经过时间的最大减少。

公开(公告)号：US20050097078A1

公开(公告)日：2005-05-05

申请号：US10698828

申请日：2003-10-31

Applicant: Guy Lohman ,  Marki Volker ,  Mir Pirahesh ,  Vijayshankar Raman ,  David Simmen

Inventor： Guy Lohman ,  Marki Volker ,  Mir Pirahesh ,  Vijayshankar Raman ,  David Simmen

IPC: G06F7/00 ,  G06F17/30

CPC classification number: G06F17/30979 ,  Y10S707/99931 ,  Y10S707/99932 ,  Y10S707/99933 ,  Y10S707/99934 ,  Y10S707/99935

Abstract: A method, system, and computer program product to make query processing more robust in the face of optimization errors. The invention validates the statistics and assumptions used for compiling a query as the query is executed and, when necessary, progressively re-optimizes the query in mid-execution based on the knowledge learned during its partial execution. The invention selectively places a number of CHECK operators in a query execution plan to validate the optimizer's cardinality estimates against actual cardinalities. Errors beyond a threshold trigger re-optimization, and the optimizer decides whether the old plan is still optimal and whether to re-use previously computed results. The invention addresses arbitrary SQL queries whose plans can contain sub-queries, updates, trigger checking, and view maintenance operations. The invention can handle concurrent update transactions or updates of common sub-expressions in a query execution plan without compromising consistency and isolation as locking information is tied to the record ID.

Abstract translation: 一种方法，系统和计算机程序产品，使查询处理在面对优化错误时更加鲁棒。 本发明验证了在执行查询时用于编译查询的统计和假设，并且在必要时，根据在其部分执行期间学到的知识，在中间执行中逐渐重新优化查询。 本发明选择性地将多个CHECK运算符放置在查询执行计划中以根据实际基数验证优化器的基数估计。 超出阈值的错误触发重新优化，优化器决定旧计划是否仍然最优，以及是否重新使用先前计算的结果。 本发明解决任意SQL查询，其计划可以包含子查询，更新，触发器检查和查看维护操作。 本发明可以处理查询执行计划中的并发更新事务或公用子表达式的更新，而不会在锁定信息与记录ID相关联的情况下不影响一致性和隔离。