公开(公告)号：US11360802B2

公开(公告)日：2022-06-14

申请号：US16887980

申请日：2020-05-29

Applicant: Oracle International Corporation

Inventor： Ramesh Kumar ,  Ananth Raghavan ,  George Eadon

IPC: G06F16/22 ,  G06F9/46 ,  G06F16/23

Abstract: Techniques for processing “destructive” database statements are provided. Destructive database statements, when processed, cause metadata of a database object to be changed. Examples of such database statements include ones that delete an index, that set a column as unused, and that drop a constraint on a column. When such a statement is received, a change is made to metadata of a database object. Such a metadata change may involve setting an index as unusable, disabling a constraint, or invalidating a cursor. After the metadata change, a first time is determined. Then, it is determined when one or more database transactions that were pending at the first time have committed. After those database transaction(s) have committed, one or more operations are performed, such as dropping an index or dropping a constraint.

公开(公告)号：US20210103569A1

公开(公告)日：2021-04-08

申请号：US17125777

申请日：2020-12-17

Applicant: Oracle International Corporation

Inventor： Ananth Raghavan ,  George Eadon ,  Ramesh Kumar ,  Hermann Baer ,  Suresh Sridharan

IPC: G06F16/21

Abstract: Techniques are provided for moving data between partitions. Such a process may be performed without requiring any locks that block transactions that target a partition from being executed. Instead, such transactions may proceed while a move operation is being performed. The move operation involves copying data from the targeted partition to another partition that is hidden from (or “invisible” to) those transactions that attempt to read from or write to the partition. During the move operation, changes that are made to the partition are also reflected in a journal. Eventually, the changes reflected in the journal are drained and applied to the hidden partition. Once the partition and the hidden partition are synchronized, the identities of the partitions are swapped so that future transactions will target the previously-hidden partition instead of the previously-viewable partition.

公开(公告)号：US10417257B2

公开(公告)日：2019-09-17

申请号：US15267540

申请日：2016-09-16

Applicant: Oracle International Corporation

Inventor： Ramesh Kumar ,  Ananth Raghavan ,  George Eadon

IPC: G06F16/27 ,  G06F16/21

Abstract: Systems for managing large database systems. Storage devices hold a set of one or more subject database tables that hold subject data accessed by one or more users. A data definition statement to perform a table alteration operation (e.g., a table partition operation) over a particular table in the subject database is received, parsed, and the table alteration operation over the particular table is initiated. During the processing of the data definition statement to complete the table alteration operation, a data manipulation statement to perform a table access operation over the same table is received and parsed. The data manipulation statement is not blocked, even while the table alteration operations are ongoing. Rather, during the time that the table alteration operations are ongoing, the data manipulation statement is processed using hidden tables. After the table alteration operations have completed, incoming data manipulation statements are performed over the altered database tables.

公开(公告)号：US20170031975A1

公开(公告)日：2017-02-02

申请号：US15146799

申请日：2016-05-04

Applicant: Oracle International Corporation

Inventor： Aurosish Mishra ,  Shasank K. Chavan ,  Allison L. Holloway ,  Jesse Kamp ,  Ramesh Kumar ,  Zhen Hua Liu ,  Niloy Mukherjee ,  Amit Ganesh ,  Tirthankar Lahiri ,  Vineet Marwah

IPC: G06F17/30

CPC classification number: G06F17/30383 ,  G06F17/30339 ,  G06F17/3046 ,  G06F17/30477

Abstract: Techniques are described for materializing pre-computed results of expressions. In an embodiment, a set of one or more column units are stored in volatile or non-volatile memory. Each column unit corresponds to a column that belongs to an on-disk table within a database managed by a database server instance and includes data items from the corresponding column. A set of one or more virtual column units, and data that associates the set of one or more column units with the set of one or more virtual column units, are also stored in memory. The set of one or more virtual column units includes a particular virtual column unit storing results that are derived by evaluating an expression on at least one column of the on-disk table.

Abstract translation: 描述了用于实现预先计算的表达式结果的技术。 在一个实施例中，一组一个或多个列单元存储在易失性或非易失性存储器中。 每个列单元对应于属于由数据库服务器实例管理的数据库中的磁盘表上的列，并包括来自相应列的数据项。 一组一个或多个虚拟列单元以及将一个或多个列单元的集合与一个或多个虚拟列单元的集合相关联的数据也存储在存储器中。 一个或多个虚拟列单元的集合包括存储通过评估磁盘表的至少一列上的表达而导出的结果的特定虚拟列单元。