公开(公告)号：US20140214754A1

公开(公告)日：2014-07-31

申请号：US13754687

申请日：2013-01-30

Applicant: ORACLE INTERNATIONAL CORPORATION

Inventor： Huagang Li ,  Srikanth Bellamkonda ,  Sankar Subramanian ,  Andrew Witkowski

IPC: G06F17/30

CPC classification number: G06F17/30433 ,  G06F17/30442 ,  G06F17/30471

Abstract: According to one aspect of the invention, for a database statement that specifies evaluating reporting window functions, a computation-pushdown execution strategy may be used for the database statement. The computation-pushdown execution plan includes producer operators and consolidation operators. Each producer operator computes a respective partial aggregation for each reporting window function based on a subset of rows, and broadcasts the respective partial aggregation. Each consolidation operator fully aggregates all partial aggregations broadcasted from the producer operators. Alternatively, an extended-data-distribution-key execution plan may be used. Each producer operator sends rows based on hash keys to sort operators for computing partial aggregations for at least one reporting window function based on a subset of rows. Each consolidation operator receives and fully aggregates all partial aggregations broadcasted from the sort operators.

Abstract translation: 根据本发明的一个方面，对于指定评估报告窗口功能的数据库语句，可以对数据库语句使用计算下推执行策略。 计算下推执行计划包括生产者运营商和合并运营商。 每个生成者操作者基于行的子集来计算每个报告窗口函数的相应部分聚合，并广播相应的部分聚合。 每个合并运营商完全聚合从生产者运营商广播的所有部分聚合。 或者，可以使用扩展数据分发密钥执行计划。 每个制作者操作员根据散列键发送行，对运算符进行排序，以便根据行的子集为至少一个报告窗口函数计算部分聚合。 每个合并运算符接收并完全聚合从排序运算符广播的所有部分聚合。

公开(公告)号：US20220277010A1

公开(公告)日：2022-09-01

申请号：US17186969

申请日：2021-02-26

Applicant: Oracle International Corporation

Inventor： Yuan Zhou ,  Huagang Li

IPC: G06F16/2453 ,  G06F16/22 ,  G06F16/2455

Abstract: Computer-implemented techniques for hash-based set operations. In some embodiments, the techniques are implemented in a computer database management system to improve the computational space or time efficiency of executing database query language statements that contain one or more set operations. With the hash-based techniques, duplicate record elimination and aggregation of the component query result sets is not required before combining the sets in a set operation as the set operation itself performs aggregation on the records. As a result, the computational efficiency of performing the set operation is improved over a sort-based approach where a component query result set is not pre-sorted.

公开(公告)号：US11379476B2

公开(公告)日：2022-07-05

申请号：US16653639

申请日：2019-10-15

Applicant: Oracle International Corporation

Inventor： Sabina Petride ,  Mohamed Ziauddin ,  Praveen T. J. Kumar ,  Huagang Li ,  Andrew Witkowski ,  Sankar Subramanian

IPC: G06F16/00 ,  G06F16/2453 ,  G06F16/22 ,  G06F16/23 ,  G06F16/242

Abstract: Techniques are described for storing and maintaining, in a materialized view, bitmap data that represents a bitmap of each possible distinct value of an expression and rewriting a query for a count of distinct values of the expression using the materialized view. The materialized view contains bitmap data that represents a bitmap of each possible distinct value of a first expression, and aggregate values of additional expressions, and is stored in memory or on disk by a database system. The database system receives a query that requests a number of distinct values, of the first expression, and an aggregate value for an additional expression. In response, the database system, rewrites the query to: compute the number of distinct values by counting the bits in the bitmap data of the materialized view that are set to the first value, and obtains the aggregate value for the additional expression in the materialized view.

公开(公告)号：US10572475B2

公开(公告)日：2020-02-25

申请号：US15713365

申请日：2017-09-22

Applicant: Oracle International Corporation

Inventor： Huagang Li ,  Angela Amor ,  Sankar Subramanian ,  Chun-Chieh Lin ,  Vinita Subramanian

IPC: G06F7/00 ,  G06F17/30 ,  G06F16/2453 ,  G06F16/23 ,  G06F16/2455

Abstract: Techniques are described for leveraging column dictionaries of tables for join, group-by and expression evaluation operations. In an embodiment, a table is stored in one or more data units, each data unit's metadata containing dictionaries for stored columns. Rather than storing unencoded column values, the data units may store columns as column vectors of dictionary-encoded values, in an embodiment. When performing a join operation, a matching of values may be performed on the build-side table using the unencoded, unencoded, values stored in the join-key dictionary(s) of the probe-side table, thus, significantly reducing the number of searching and matching operations. In an embodiment, a group-by operation may be executed by performing partial aggregations based on unique group-by key values as stored in the one or more group-by key dictionaries. For an expression evaluation, only a single evaluation may be performed for each unique combination of expression-key values in a data unit by leveraging the one or more expression-key dictionaries.

公开(公告)号：US09158812B2

公开(公告)日：2015-10-13

申请号：US13754740

申请日：2013-01-30

Applicant: Oracle International Corporation

Inventor： Huagang Li ,  Srikanth Bellamkonda

IPC: G06F7/00 ,  G06F17/30

CPC classification number: G06F17/30445

Abstract: According to one aspect of the invention, for a database statement that specifies evaluating ranking or cumulative window functions, an execution strategy based on an extended data distribution key may be used for the database statement. In the execution strategy, each sort operator of multiple parallel processing sort operators computes locally evaluated results of a ranking or cumulative window function based on a subset of rows in all rows used to evaluate the database statement, and sends the first and last rows' locally evaluated results to a query coordinator. The query coordinator consolidates the locally evaluated results received from the multiple parallel processing sort operators and sends consolidated results to the sort operators based on their respective demographics. Each sort operator completes full evaluation of the ranking or cumulative window functions based at least in part on one or more of the consolidated results provided by the query coordinator.

Abstract translation: 根据本发明的一个方面，对于指定评估排名或累积窗口函数的数据库语句，可以对数据库语句使用基于扩展数据分配密钥的执行策略。 在执行策略中，多个并行处理排序运算符的每个排序运算符基于用于评估数据库语句的所有行中的行的子集来计算排名或累积窗口函数的本地评估结果，并将第一行和最后一行“ 评估结果给查询协调器。 查询协调器整合从多个并行处理排序运算符接收的本地评估结果，并根据各自的人口统计特征将综合结果发送给排序运算符。 每个排序运算符至少部分地基于查询协调器提供的一个或多个综合结果完成对排名或累积窗函数的完全评估。