公开(公告)号：US08694551B2

公开(公告)日：2014-04-08

申请号：US12963506

申请日：2010-12-08

Applicant: Ravishankar Ramamurthy ,  Kaushik Shiriraghav

Inventor： Ravishankar Ramamurthy ,  Kaushik Shiriraghav

IPC: G06F7/00

CPC classification number: G06F17/30289

Abstract: Methods and systems for auditing queries using query differentials are disclosed. A method includes identifying a set of queries, determining if results of each query of the set of queries are different from results of respective differentials of each query of the set of queries, and based on the determining, making a characterization of each query of the set of queries as one of safe and unsafe. Access is provided to the characterization of each query of the set of queries.

Abstract translation: 公开了使用查询差异来审计查询的方法和系统。 一种方法包括识别一组查询，确定该组查询的每个查询的结果是否与该组查询的每个查询的相应差异的结果不同，并且基于确定，对每个查询的每个查询进行表征 一组查询作为安全和不安全的一个。 访问被提供给查询集合的每个查询的表征。

公开(公告)号：US20120150877A1

公开(公告)日：2012-06-14

申请号：US12964549

申请日：2010-12-09

Applicant: Ravishankar Ramamurthy ,  Abhijeet Mohapatra

Inventor： Ravishankar Ramamurthy ,  Abhijeet Mohapatra

IPC: G06F17/30

CPC classification number: G06F16/20

Abstract: A method for compressing data. The method includes accessing, within an electronic system, a database relation comprising a plurality of attributes and determining a sort order of the plurality of attributes of the database relation. The method further includes determining an order of a plurality of compression operators operable to compress the database relation and compressing the database relation to produce a compressed database based on the sort order and the order of the plurality compression operators.

Abstract translation: 一种压缩数据的方法。 该方法包括在电子系统内访问包括多个属性的数据库关系，并确定数据库关系的多个属性的排序顺序。 该方法还包括确定可操作以压缩数据库关系的多个压缩算子的顺序，并且基于多个压缩算子的排序顺序和顺序来压缩数据库关系以产生压缩数据库。

公开(公告)号：US08190595B2

公开(公告)日：2012-05-29

申请号：US12413544

申请日：2009-03-28

Applicant: Nicolas Bruno ,  Ravishankar Ramamurthy ,  Surajit Chaudhuri

Inventor： Nicolas Bruno ,  Ravishankar Ramamurthy ,  Surajit Chaudhuri

IPC: G06F17/30

CPC classification number: G06F17/30386

Abstract: A flexible query hints system and method for discovering and expressing query hints in a database management system. Embodiments of the flexible query hints system and method include a power hints (Phints) language that enables the specification of constraints to influence a query optimizer. Phints expressions are defined as tree patterns annotated with constraints. Embodiments of the flexible query hints system and method also include techniques to incorporate the power hints language expressions into an extended query optimizer. Theses techniques include computing a directed acyclic graph for Phints expression, deriving candidate matches using the Phints expression and the graph, computing candidate matches, and extracting a revised execution plan having a lowest cost and satisfying constraints of the Phints expression. Embodiments of the flexible query hints system and method include a flexible query hint user interface that allow users to interactively adjust query hints.

Abstract translation: 灵活的查询提示系统和方法，用于在数据库管理系统中发现和表达查询提示。 灵活查询提示系统和方法的实施例包括能够指定约束来影响查询优化器的功率提示（Phints）语言。 Phints表达式定义为使用约束注释的树模式。 灵活查询提示系统和方法的实施例还包括将功能提示语言表达式并入到扩展查询优化器中的技术。 这些技术包括计算用于Phints表达的有向非循环图，使用Phints表达式和图形导出候选匹配，计算候选匹配，以及提取具有最低成本并满足Phints表达式的约束的经修订的执行计划。 灵活查询提示系统和方法的实施例包括灵活的查询提示用户界面，允许用户交互地调整查询提示。

公开(公告)号：US20110313999A1

公开(公告)日：2011-12-22

申请号：US12817511

申请日：2010-06-17

Applicant: Nicolas Bruno ,  Ravishankar Ramamurthy ,  Surajit Chaudhuri ,  Vivek Ravindranath Narasayya

Inventor： Nicolas Bruno ,  Ravishankar Ramamurthy ,  Surajit Chaudhuri ,  Vivek Ravindranath Narasayya

IPC: G06F17/30

CPC classification number: G06F16/24537 ,  G06F16/24542

Abstract: A relational database server may concurrently execute many relational queries, but a complex relational query may cause performance delays in the fulfillment of other relational queries. Instead, the relational database server may generate a query plan for the relational query, and may endeavor to partition the relational query between a spool operator and a scan operator into two or more query slices, where each query slice may be executed within a query slice threshold. Many alternative candidate query plans may be considered, such as inserting spool and scan operators after various operators and parameterizing operators in order to partition the records of a relation into two or more ranges based on an attribute of the relation. A large search space of candidate query plans may be reviewed in order to select a query plan that respects the query slice threshold while efficiently executing the logic of the relational query.

Abstract translation: 关系数据库服务器可以同时执行许多关系查询，但是复杂的关系查询可能导致履行其他关系查询的性能延迟。 相反，关系数据库服务器可以生成关系查询的查询计划，并且可以尝试将线程运算符和扫描运算符之间的关系查询划分成两个或更多个查询片段，其中每个查询片段可以在查询片段内执行 阈。 可以考虑许多备选候选查询计划，例如在各种运算符和参数化运算符之后插入假脱机和扫描运算符，以便基于关系的属性将关系的记录分成两个或更多个范围。 可以检查候选查询计划的大搜索空间，以便在有效执行关系查询的逻辑的同时选择尊重查询片段阈值的查询计划。

公开(公告)号：US07958114B2

公开(公告)日：2011-06-07

申请号：US12098178

申请日：2008-04-04

Applicant: Surajit Chaudhuri ,  Vivek Narasayya ,  Ravishankar Ramamurthy

Inventor： Surajit Chaudhuri ,  Vivek Narasayya ,  Ravishankar Ramamurthy

IPC: G06F7/00 ,  G06F17/30

CPC classification number: G06F17/30306 ,  G06Q30/0202

Abstract: A database server may be configured to compute distinct page counts of pages accessed to execute operands of respective queries. The queries may be executed against a table comprised of the pages and having an index managed by the database server. The distinct page counts may be obtained by counting, as a part of the executing of the queries, distinct pages accessed during the execution of the queries.

Abstract translation: 数据库服务器可以被配置为计算被访问的页面的不同页面计数以执行各个查询的操作数。 可以针对由该页组成的表并且具有由数据库服务器管理的索引来执行查询。 独立页面计数可以通过在执行查询期间计数访问的不同页面作为执行查询的一部分来获得。

公开(公告)号：US20050222965A1

公开(公告)日：2005-10-06

申请号：US10813963

申请日：2004-03-31

Applicant: Surajit Chaudhuri ,  Vivek Narasayya ,  Ravishankar Ramamurthy

Inventor： Surajit Chaudhuri ,  Vivek Narasayya ,  Ravishankar Ramamurthy

IPC: G06F7/00 ,  G06F17/30

CPC classification number: G06F17/30522 ,  G06F17/30306 ,  Y10S707/99932 ,  Y10S707/99945 ,  Y10S707/99948

Abstract: A query progress indicator that provides an indication to a user of the progress of a query being executed on a database. The indication of the progress of the query allows the user to decide whether the query should be allowed to complete or should be aborted. One method that may be used to estimate the progress of a query that is being executed on a database defines a model of work performed during execution of a query. The total amount of work that will be performed during execution of the query is estimated according to the model. The amount of work performed at a given point during execution of the query is estimated according to the model. The progress of the query is estimated using the estimated amount of work at the given point in time and the estimated total amount of work. This estimated progress of query execution may be provided to the user.

Abstract translation: 查询进度指示符，向用户提供在数据库上执行的查询的进度的指示。 查询进度的指示允许用户决定是否允许查询完成或应该被中止。 可用于估计在数据库上执行的查询的进度的一种方法定义了在查询执行过程中执行的工作模型。 根据模型估计执行查询期间执行的总工作量。 在执行查询期间在给定点执行的工作量根据模型进行估计。 查询的进度使用在给定时间点的估计工作量和估计的总工作量来估计。 可以向用户提供该估计的查询执行进度。

公开(公告)号：US06725848B2

公开(公告)日：2004-04-27

申请号：US10052013

申请日：2002-01-18

Applicant: Ravishankar Ramamurthy ,  Sameer Bhargara ,  Phillip F. Rimnac

Inventor： Ravishankar Ramamurthy ,  Sameer Bhargara ,  Phillip F. Rimnac

IPC: F02M2507

CPC classification number: F02D41/005 ,  F02B29/0425 ,  F02D2200/0418 ,  F02M26/05 ,  F02M26/10 ,  F02M26/16 ,  F02M26/28 ,  F02M26/33 ,  F02M26/47 ,  F02M26/50 ,  Y02T10/47

Abstract: An exhaust gas recirculation system for a compression ignition engine is provided wherein the exhaust gas recirculation is shut off depending upon the sensed or calculated humidity in the intake manifold relative to the dew point of the exhaust/intake air mixture. The humidity of the exhaust/intake air mixture may be measured in the intake manifold, charge air mixer or the ambient humidity may be sensed. If humidity is measured in the air charge mixer or in the ambient air, other factors such as engine speed and load, intake manifold pressure, EGR flow and air/fuel ratio may be used to calculate the humidity in the intake manifold. When the temperature of the mixture in the intake manifold is less than the dew point of the mixture, the engine control strategy may be shut off the EGR to prevent condensation in the exhaust gas recirculation system or engine.

Abstract translation: 提供了一种用于压缩点火发动机的废气再循环系统，其中废气再循环根据进气歧管中感测或计算的湿度相对于排气/进气混合物的露点而被切断。 排气/进气混合物的湿度可以在进气歧管中测量，可以感测加气空气混合器或环境湿度。 如果在空气充气混合器或环境空气中测量湿度，则可以使用诸如发动机转速和负载，进气歧管压力，EGR流量和空气/燃料比等其他因素来计算进气歧管中的湿度。 当进气歧管中的混合物的温度低于混合物的露点时，发动机控制策略可以关闭EGR以防止废气再循环系统或发动机中的冷凝。

公开(公告)号：US08108154B2

公开(公告)日：2012-01-31

申请号：US12331884

申请日：2008-12-10

Applicant: Ravishankar Ramamurthy ,  Shouxian Ren

Inventor： Ravishankar Ramamurthy ,  Shouxian Ren

IPC: G06N31/00 ,  F01N3/00

CPC classification number: F01N9/00 ,  F01N3/2066 ,  F01N2900/0601 ,  F01N2900/08 ,  F01N2900/12 ,  F01N2900/1402 ,  Y02A50/2325 ,  Y02T10/24 ,  Y02T10/47

Abstract: A NOx estimation system includes an operating mode determination module that determines an operating mode of an engine, and an emission prediction module. The emission prediction module estimates NOx emission based on the operating mode, a plurality of sensed parameters, and a map. The map correlates the plurality of sensed parameters to the NOx emission based on the operating mode.

Abstract translation: NOx估计系统包括确定发动机的运行模式的运行模式确定模块和排放预测模块。 排放预测模块基于操作模式，多个感测参数和地图来估计NOx排放。 该地图基于操作模式将多个感测参数与NOx排放相关联。

公开(公告)号：US07739269B2

公开(公告)日：2010-06-15

申请号：US11625153

申请日：2007-01-19

Applicant: Surajit Chaudhuri ,  Ravishankar Ramamurthy

Inventor： Surajit Chaudhuri ,  Ravishankar Ramamurthy

IPC: G06F7/00 ,  G06F17/30

CPC classification number: G06F17/30463

Abstract: Database systems use a plan cache to avoid the overheads (e.g., time, money) of query recompilation. Query plans can become invalidated by updates to the statistics on data or changes to the physical database design. Once a plan is invalidated, it can be repaired utilizing one or more of the disclosed embodiments. Incremental repair of query plans includes reusing parts of the current plan rather than discarding the plan entirely when it is invalidated. Repair to an existing query plan is attempted before resorting to full recompilation.

Abstract translation: 数据库系统使用计划缓存来避免查询重新编译的开销（如时间，金钱）。 通过对数据统计信息的更新或物理数据库设计更改，查询计划可能会失效。 一旦计划无效，可以利用所公开的一个或多个实施例来修复计划。 查询计划的增量修复包括重新使用当前计划的部分，而不是完全在无效的情况下丢弃计划。 在进行完全重新编译之前尝试修复现有的查询计划。

公开(公告)号：US20090083238A1

公开(公告)日：2009-03-26

申请号：US11859046

申请日：2007-09-21

Applicant: Surajit Chaudhuri ,  Shriraghav Kaushik ,  Abhijit Pol ,  Ravishankar Ramamurthy

Inventor： Surajit Chaudhuri ,  Shriraghav Kaushik ,  Abhijit Pol ,  Ravishankar Ramamurthy

IPC: G06F17/30

CPC classification number: G06F16/24561

Abstract: Stop-and-restart query execution that partially leverages the work already performed during the initial execution of the query to reduce the execution time during a restart. The technique selectively saves information from a previous execution of the query so that the overhead associated with restarting the query execution can be bounded. Despite saving only limited information, the disclosed technique substantially reduces the running time of the restarted query. The stop-and-restart query execution technique is constrained to save and reuse only a bounded number of records (intermediate records or output records) thereby releasing all other resources, rather than some of the resources. The technique chooses a subset of the records to save that were found during normal execution and then skipping the corresponding records when performing a scan during restart to prevent the duplication of execution. A skip-scan operator is employed to facilitate the disclosed restart technique.

Abstract translation: 停止和重新启动的查询执行，部分利用在初始执行查询期间已经执行的工作，以减少重新启动期间的执行时间。 该技术选择性地保存来自查询的先前执行的信息，使得与重新启动查询执行相关联的开销可以被界定。 尽管仅节省有限的信息，但是所公开的技术大大减少了重新启动的查询的运行时间。 停止和重启查询执行技术被限制为只保存和重用有限数量的记录（中间记录或输出记录），从而释放所有其他资源，而不是一些资源。 该技术选择在正常执行期间发现的记录的子集，然后在重新启动期间执行扫描时跳过相应的记录，以防止重复执行。 采用跳过扫描运算符来促进公开的重启技术。