公开(公告)号：US10698771B2

公开(公告)日：2020-06-30

申请号：US15266375

申请日：2016-09-15

Applicant: Oracle International Corporation

Inventor： Hongjie Yang ,  Yunrui Li ,  Mahesh Baburao Girkar

IPC: G06F7/00 ,  G06F17/00 ,  G06F11/14 ,  G06F16/27 ,  G06F11/20

Abstract: Herein are techniques of zero data loss with asynchronously replicated redo logs. In an embodiment, a first server instance (FSI) of a plurality of server instances (PSI) of a primary database (PDB) sends, to a standby database (SDB) during an shutdown of FSI, a first recovery count (RC) and a remainder of an instance redo log (IRL). In response to recovering FSI, a second server instance of PSI increments a recovery counter to a second RC (SRC), publishes SRC to PSI, and sends SRC to SDB. After restarting FSI, FSI makes a change to contents of PDB, and stores, into IRL, a redo entry that defines the change. During failover, a database management system (DBMS) detects whether RCs associated with FSRL and SSRL are unanimous. If unanimous, DBMS fully rolls forward SDB by replaying FSRL and SSRL. Otherwise, DBMS limits replay and indicates that FSRL and SSRL might be inconsistent.

公开(公告)号：US09563655B2

公开(公告)日：2017-02-07

申请号：US13791517

申请日：2013-03-08

Applicant: Oracle International Corporation

Inventor： Jin-Jwei Chen ,  Benedicto Elmo Garin, Jr. ,  Mahesh Baburao Girkar ,  Raymond Guzman

IPC: G06F17/30

CPC classification number: G06F17/30371 ,  G06F17/30368 ,  G06F17/30575

Abstract: A method, system and computer program product for low loss database backup and recovery. The method commences by transmitting, by a first server to a third server, a copy of a database snapshot backup, the transmitting commencing at a first time. Then capturing, by the first server, a stream of database redo data, the capturing commencing before or upon transmitting the database snapshot backup, and continuing until a third time. The stream of database redo data is received by an intermediate server after which the intermediate server transmits the stream of database redo data to the third server. Now, the third server has the database snapshot backups and the database redo data. The third server can send to a fourth server all or portion of the database redo data to be applied to the copy of the database snapshot backup restored there to create a restored database.

Abstract translation: 一种用于低损失数据库备份和恢复的方法，系统和计算机程序产品。 该方法通过由第一服务器向第三服务器发送数据库快照备份的副本，该传输从第一次开始。 然后，由第一台服务器捕获数据库重做数据流，捕获在发送数据库快照备份之前或之后开始，并持续至第三次。 数据库重做数据流由中间服务器接收，中间服务器将数据库重做数据流发送到第三个服务器。 现在，第三台服务器具有数据库快照备份和数据库重做数据。 第三台服务器可以向第四台服务器发送要应用于数据库快照备份副本的全部或部分数据库重做数据，以恢复其中的数据库快照备份，以创建还原的数据库。

公开(公告)号：US20150317212A1

公开(公告)日：2015-11-05

申请号：US14270117

申请日：2014-05-05

Applicant: Oracle International Corporation

Inventor： Jonghyun Lee ,  Yunrui Li ,  Mahesh Baburao Girkar ,  Amrish Srivastava

IPC: G06F11/14

CPC classification number: G06F11/2038 ,  G06F11/1438 ,  G06F11/1458 ,  G06F11/2097 ,  G06F17/30067 ,  G06F17/30353 ,  G06F2201/80 ,  G06F2201/82 ,  G06F2201/835

Abstract: A method, apparatus, and system for a time-based checkpoint target is provided for standby databases. Change records received from a primary database are applied for a standby database, creating dirty buffer queues. As the change records are applied, a mapping is maintained, which maps timestamps to logical times of change records that were most recently applied at the timestamp for the standby database. On a periodic dirty buffer queue processing interval, the mapping is used to determine a target logical time that is mapped to a target timestamp that is prior to a present timestamp by at least a checkpoint delay. The dirty buffer queues are then processed up to the target logical time, creating an incremental checkpoint. On a periodic header update interval, file headers reflecting a consistent logical time for the checkpoint are also updated. The intervals and the checkpoint delay are adjustable by user or application.

Abstract translation: 为备用数据库提供了基于时间的检查点目标的方法，装置和系统。 将从主数据库接收的更改记录应用于备用数据库，从而创建脏缓冲区队列。 随着应用更改记录，维护映射，将时间戳映射到最近在备用数据库的时间戳处应用的更改记录的逻辑时间。 在周期性的脏缓冲器队列处理间隔上，该映射用于确定映射到当前时间戳之前至少一个检查点延迟的目标时间戳的目标逻辑时间。 然后将脏缓冲区队列处理到目标逻辑时间，创建一个增量检查点。 在周期性头文件更新间隔中，还会更新反映检查点一致逻辑时间的文件头。 间隔和检查点延迟可由用户或应用程序调整。

公开(公告)号：US20150120659A1

公开(公告)日：2015-04-30

申请号：US14067129

申请日：2013-10-30

Applicant: ORACLE INTERNATIONAL CORPORATION

Inventor： Amrish Srivastava ,  Yunrui Li ,  Mahesh Baburao Girkar

IPC: G06F17/30

CPC classification number: G06F17/30575 ,  G06F11/14 ,  G06F11/2038 ,  G06F11/2094 ,  G06F11/2097 ,  G06F2201/80

Abstract: A method, apparatus, and system for multi-instance redo apply is provided for standby databases. A multi-instance primary database generates a plurality of redo records, which are received and applied by a physical standby running a multi-instance standby database. Each standby instance runs a set of processes that utilize non-blocking, single-task threads for high parallelism. At each standby instance for the multi-instance redo, the plurality of redo records are merged into a stream from one or more redo strands in logical time order, distributed to standby instances according to determined apply slave processes using an intelligent workload distribution function, remerged after receiving updates from remote instances, and applied in logical time order by the apply slave processes. Redo apply progress is tracked at each instance locally and also globally, allowing a consistent query logical time to be maintained and published to service database read query requests concurrently with the redo apply.

Abstract translation: 为备用数据库提供了一种用于多实例重做应用的方法，装置和系统。 多实例主数据库生成多个重做记录，这些记录由运行多实例备用数据库的物理备用程序接收和应用。 每个备用实例运行一组使用非阻塞单任务线程进行高并行化的进程。 在多实例重做的每个备用实例上，多个重做记录以逻辑时间顺序被合并到来自一个或多个重做链的流中，根据使用智能工作负载分布函数确定的应用从属进程分发到备用实例 在从远程实例接收到更新后，并通过应用从属进程以逻辑时间顺序应用。 重做应用进度在本地和全局的每个实例被跟踪，允许一致的查询逻辑时间被维护和发布，以与重做应用程序同时服务于数据库读取查询请求。