公开(公告)号：US09430550B2

公开(公告)日：2016-08-30

申请号：US13629897

申请日：2012-09-28

Applicant: Oracle International Corporation

Inventor： Mohamed Ziauddin ,  Andrew Witkowski

IPC: G06F17/30

CPC classification number: G06F17/30592 ,  G06F17/30289 ,  G06F17/30584 ,  G06F17/30598

Abstract: Techniques are provided that address the problems associated with prior approaches for clustering a fact table in a relational database management system. According to one aspect of the invention, a database server clusters a fact table in a database based on one or more dimension tables. More specifically, rows are stored in the fact table in a sorted order and the order in which the rows are sorted is based on values in one or more columns of one or more of the dimension tables. A user specifies the columns of the dimension tables on which the sorted order is based in “clustering criteria”. The database server uses the clustering criteria to automatically store the rows in the fact table in the sorted order in response to certain user-initiated database operations on the fact-table.

Abstract translation: 提供了解决与在关系数据库管理系统中聚类事实表的先前方法相关联的问题的技术。 根据本发明的一个方面，数据库服务器基于一个或多个维度表将数据库中的事实表聚类。 更具体地说，行以排序的顺序存储在事实表中，并且行被排序的顺序基于一个或多个维度表的一个或多个列中的值。 用户在“聚类标准”中指定排序顺序所基于的维度表的列。 数据库服务器使用聚类标准来按照排序顺序自动将事务表中的行存储在事实表中的某些用户启动的数据库操作上。

公开(公告)号：US20250139092A1

公开(公告)日：2025-05-01

申请号：US18384231

申请日：2023-10-26

Applicant: Oracle International Corporation

Inventor： Hong Su ,  Jiakun Li ,  Suratna Budalakoti ,  Mohamed Ziauddin ,  Alan Paul Wood

IPC: G06F16/2453 ,  G06F16/22

Abstract: A histogram-augmented dynamic sampling approach is provided for determining cardinality of a two-table join. The approach has a pre-processing phase in which data structures are created that will be used during a compilation phase for cardinality estimation. These data structures include a row histogram and a key histogram, which are created for selected columns of a first table. A cardinality estimation phase uses the data structures to estimate the cardinality of various joins at the time of query compilation. In this phase, the system executes queries that join the histograms with a second table, to perform the cardinality estimation.

公开(公告)号：US20240078233A1

公开(公告)日：2024-03-07

申请号：US17902615

申请日：2022-09-02

Applicant: Oracle International Corporation

Inventor： Krishna Kantikiran Pasupuleti ,  Hong Su ,  Jiakun Li ,  Mohamed Ziauddin

IPC: G06F16/2453 ,  G06F11/34 ,  G06F16/2455

CPC classification number: G06F16/24542 ,  G06F11/3419 ,  G06F16/24552

Abstract: Techniques for automatic error mitigation in database systems using alternate plans are provided. After receiving a database statement, an error is detected as a result of compiling the database statement. In response to detecting the error, one or more alternate plans that were used to process the database statement or another database statement that is similar to the database statement are identified. A particular alternate plan of the one or more alternate plans is selected. A result of the database statement is generated based on processing the particular alternate plan.

公开(公告)号：US20230024553A1

公开(公告)日：2023-01-26

申请号：US17380905

申请日：2021-07-20

Applicant: ORACLE INTERNATIONAL CORPORATION

Inventor： Rafi Ahmed ,  Mohamed Ziauddin ,  Sankar Subramanian

IPC: G06F16/2453

Abstract: Techniques for subsumption of inline views and subqueries in a query are described. An optimization technique of subsumption is enabled by inline views having identical tables and identical join conditions and having aggregation functions but no group-by clauses. When subsumption takes place, a single query block replaces the inline views (or subqueries) with a single inline view query block. Subsumption reduces multiple access to the same table and multiple evaluations of the same join conditions required to evaluate the query. The single query block includes factored out filter predicates and unified predicates that originate from the subsumed inline views (or subqueries). Based on similarities among the aggregation functions and filter predicates in the subsumed inline views, pre-computation of common aggregates may be performed in a new group-by view in the subsuming view.

公开(公告)号：US20220222254A1

公开(公告)日：2022-07-14

申请号：US17707643

申请日：2022-03-29

Applicant: Oracle International Corporation

Inventor： Mohamed Ziauddin ,  Zhe Wu ,  Andrew Witkowski

IPC: G06F16/2453 ,  G06F16/901

Abstract: Embodiments generate random walks through a directed graph that is represented in a relational database table. Each row of the graph table represents a directed edge in the graph and includes a source vertex and a destination vertex. Each row is further augmented to (a) indicate the number of outbound edges starting from the destination vertex in the row and (b) include an identifier that distinguishes the edge from other outbound edges starting from the same source vertex. An SQL query may be executed on the augmented graph table. Starting from a source vertex (starting vertex or the destination vertex of the previously selected hop) the query randomly selects a row of the graph table representing one of the outbound edges from the source vertex and adds the selected outbound edge as a row in a random walk table that represents the next hop in the random walk.

公开(公告)号：US11334567B2

公开(公告)日：2022-05-17

申请号：US16543258

申请日：2019-08-16

Applicant: Oracle International Corporation

Inventor： Mohamed Ziauddin ,  Zhe Wu ,  Andrew Witkowski

IPC: G06F16/2453 ,  G06F16/901

Abstract: Embodiments generate random walks through a directed graph that is represented in a relational database table. Each row of the graph table represents a directed edge in the graph and includes a source vertex and a destination vertex. Each row is further augmented to (a) indicate the number of outbound edges starting from the destination vertex in the row and (b) include an identifier that distinguishes the edge from other outbound edges starting from the same source vertex. An SQL query may be executed on the augmented graph table. Starting from a source vertex (starting vertex or the destination vertex of the previously selected hop) the query randomly selects a row of the graph table representing one of the outbound edges from the source vertex and adds the selected outbound edge as a row in a random walk table that represents the next hop in the random walk.

公开(公告)号：US20210109930A1

公开(公告)日：2021-04-15

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

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：US09659039B2

公开(公告)日：2017-05-23

申请号：US14033380

申请日：2013-09-20

Applicant: Oracle International Corporation

Inventor： Mohamed Ziauddin ,  Andrew S.C. Witkowski ,  You Jung Kim

IPC: G06F17/30

CPC classification number: G06F17/30289

Abstract: Computer systems, machine-implemented methods, and stored instructions are provided herein for maintaining information that describes aggregate characteristics of data within zones. Stored data may be separated into defined zone(s). Data structure(s), such as zone map(s), may store, for each of the zone(s), aggregate characteristic(s) of data in the zone, and a stored indication of whether or not the zone is stale. When a change is made to data in a particular zone that was not stale, a zone manager causes the particular zone to become stale if the change can result in the particular zone having data that is not included in the particular zone's stored aggregate characteristic(s). On the other hand, if the change cannot result in the particular zone having data that is not included in the particular zone's stored aggregate characteristic(s), then the zone manager does not cause the particular zone to become stale.

公开(公告)号：US20150199407A1

公开(公告)日：2015-07-16

申请号：US14671510

申请日：2015-03-27

Applicant: Oracle International Corporation

Inventor： Mohamed Ziauddin ,  Andrew Witkowski

IPC: G06F17/30

CPC classification number: G06F17/30492 ,  G06F17/30584 ,  G06F17/30592 ,  G06F17/30598

Abstract: Techniques are provided for generating a “dimensional zonemap” that allows a database server to avoid scanning disk blocks of a fact table based on filter predicates in a query that qualify one or more dimension tables. The zonemap divides the fact table into sets of contiguous disk blocks referred to as “zones”. For each zone, a minimum value and a maximum value for each of one or more “zoned” columns of the dimension tables is determined and maintained in the zonemap. For a query that contains a filter predicate on a zoned column, the predicate value can be compared to the minimum value and maximum value maintained for a zone for that zoned column to determine whether a scan of the disk blocks of the zone can be skipped.

Abstract translation: 提供了用于生成“维度zonemap”的技术，允许数据库服务器基于限定一个或多个维度表的查询中的过滤器谓词来扫描事实表的磁盘块。 zonemap将事实表划分为被称为“区域”的连续磁盘块的集合。 对于每个区域，维度表的一个或多个“分区”列中的每一个的最小值和最大值在zonemap中确定和维护。 对于在分区列上包含过滤谓词的查询，可以将谓词值与该分区列的区域维护的最小值和最大值进行比较，以确定是否可以跳过该区域的磁盘块扫描。