公开(公告)号：US20230050727A1

公开(公告)日：2023-02-16

申请号：US17974152

申请日：2022-10-26

Applicant: Oracle International Corporation

Inventor： Jesse Kamp ,  Allison L. Holloway ,  Meichun Hsu ,  Hideaki Kimura ,  Boris Klots ,  Vasudha Krishnaswamy ,  Kartik Kulkarni ,  Teck Hua Lee ,  Yunrui Li ,  Aurosish Mishra ,  Ajit Mylavarapu ,  Sukhada Pendse ,  Garret F. Swart ,  Shasank K. Chavan ,  Tirthankar Lahiri ,  Juan R. Loaiza

IPC: G06F16/22 ,  G06F16/27 ,  G06F16/21 ,  G06F16/174 ,  G06F16/18 ,  G06F16/23 ,  G06F16/11

Abstract: A shared-nothing database system is provided in which parallelism and workload balancing are increased by assigning the rows of each table to “slices”, and storing multiple copies (“duplicas”) of each slice across the persistent storage of multiple nodes of the shared-nothing database system. When the data for a table is distributed among the nodes of a shared-nothing system in this manner, requests to read data from a particular row of the table may be handled by any node that stores a duplica of the slice to which the row is assigned. For each slice, a single duplica of the slice is designated as the “primary duplica”. All DML operations (e.g. inserts, deletes, updates, etc.) that target a particular row of the table are performed by the node that has the primary duplica of the slice to which the particular row is assigned. The changes made by the DML operations are then propagated from the primary duplica to the other duplicas (“secondary duplicas”) of the same slice.

公开(公告)号：US11061884B2

公开(公告)日：2021-07-13

申请号：US16163181

申请日：2018-10-17

Applicant: ORACLE INTERNATIONAL CORPORATION

Inventor： Yunrui Li

IPC: G06F11/00 ,  G06F16/23 ,  G06F11/14 ,  G06F12/0804

Abstract: Described is an improved approach to implement parallel queries where session states are saved for parallelization resources. When work needs to be performed in the parallel query system for a given session, a search can be performed to identify a resource (from among the pool of available resources) that had previously been used by that session, and which had saved a session state object for that previous connection to the session. Instead of incurring the entirety of setup costs each time workload is assigned to a resource, the saved session state can be used to re-set the context for the resource to the configuration requirements for that session.

公开(公告)号：US20210081242A1

公开(公告)日：2021-03-18

申请号：US16570895

申请日：2019-09-13

Applicant: Oracle International Corporation

Inventor： Graham Ivey ,  Yunrui Li

IPC: G06F9/48 ,  G06F9/4401 ,  G06F9/54 ,  G06F16/25

Abstract: A computer's processes and/or threads generate and store in memory, data to reimplement or reverse a transaction on a database, so that the database can be recovered. This data is written to persistent memory storage (“persisted”) by another process, for which the processes and/or threads may wait. This wait includes at least a sleep phase, and additionally a spin phase which is entered if after awakening from sleep and checking (“on-awakening” check), the data to be persisted is found to not have been persisted. To sleep in the sleep phase, each process/thread specifies a sleep duration determined based at least partially on previous results of on-awakening checks. The previous results in which to-be-persisted data was found to be not persisted are indications the sleeps were insufficient, and these indications are counted and used to determine the sleep duration. Repeated determination of sleep duration makes the sleep phase adaptive.

公开(公告)号：US10789131B2

公开(公告)日：2020-09-29

申请号：US15254884

申请日：2016-09-01

Applicant: Oracle International Corporation

Inventor： Kumar Rajamani ,  Muthu Olagappan ,  Yunrui Li ,  Giridhar Ravipati ,  Jing Zheng

IPC: G06F11/14 ,  G06F16/27

Abstract: Techniques are provided for creating a backup of a source pluggable database (SPD) of a source container database and porting the backup for recovery into a different target container database. In an embodiment, a source database server retrieves metadata that describes backups of the SPD. The source database server inserts, into an unplugged pluggable database of the SPD, the metadata that describes each of the backups. For example, unplugging the SPD may automatically create the unplugged pluggable database. Eventually, the unplugged pluggable database may be plugged into the target container database. A target database server transfers the metadata that describes each of the backups from the unplugged pluggable database and into the target container database. Based on at least one backup and the metadata that describes backups of the SPD, the target database server restores a target pluggable database within the target container database.

公开(公告)号：US10706009B2

公开(公告)日：2020-07-07

申请号：US13831489

申请日：2013-03-14

Applicant: Oracle International Corporation

Inventor： Chi Cao Minh ,  Yunrui Li ,  Jonghyun Lee

IPC: G06F16/13

Abstract: Techniques are provided for managing cached data objects in a mixed workload environment. In an embodiment, a system, log data is stored in one or more buffers. In response to receiving a request to perform a logical write, a first process writes a first portion of the log data to a log file in persistent storage. While the first portion of the log data is being written to the log file, a second process writes a second portion of the log data in the one or more buffers to the log file in persistent storage. In another embodiment, a request to perform a second logical write may be received before the first logical write completes. While the first log data is being written to the log file, one or more processes write second log data for the second logical write to the log file.

公开(公告)号：US10599630B2

公开(公告)日：2020-03-24

申请号：US14726133

申请日：2015-05-29

Applicant: Oracle International Corporation

Inventor： Yunrui Li

IPC: G06F16/23

Abstract: A method and apparatus for elimination of log file synchronization delay at transaction commit time is provided. One or more change records corresponding to a database transaction are generated. One or more buffer entries comprising the one or more change records are entered into a persistent change log buffer. A commit operation is performed by generating a commit change record corresponding to the database transaction and entering a commit buffer entry comprising the commit change record into the persistent change log buffer. The commit operation returns without waiting for the commit change record to be recorded in a change record log file.

公开(公告)号：US10152396B2

公开(公告)日：2018-12-11

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: G06F17/30 ,  G06F11/00 ,  G06F11/20 ,  G06F11/14

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.

公开(公告)号：US10055250B2

公开(公告)日：2018-08-21

申请号：US14059352

申请日：2013-10-21

Applicant: Oracle International Corporation

Inventor： Wei Hu ,  Yunrui Li ,  Vinay Srihari ,  Ramana Yerneni

IPC: G06F17/30 ,  G06F9/46 ,  G06F11/14 ,  G06F11/20

CPC classification number: G06F9/46 ,  G06F11/1464 ,  G06F11/1471 ,  G06F11/2035 ,  G06F11/2046 ,  G06F11/2097 ,  G06F2201/80

Abstract: Each of a plurality of Worker processes are allowed to perform any and all of the following tasks involving logged work items: (1) reading a subset of the work items from a log; (2) sequentially ordering work items for corresponding data objects; (3) applying a sequentially ordered set of work items to a corresponding data object; and (4) transmitting a subset of work items to a Worker process running on another database server in a cluster, if necessary. These tasks can be performed concurrently, at will, and as available, by the Worker processes. An improved checkpointing technique eliminates the need for the Worker processes to get to a synchronization point and stop. Instead, a Coordinator process examines the current state of progress of the Worker processes and computes a past point in the sequence of work items at which all work items before that point have been completely processed, and records this point as the checkpoint.

公开(公告)号：US09928147B2

公开(公告)日：2018-03-27

申请号：US15014969

申请日：2016-02-03

Applicant: Oracle International Corporation

Inventor： Yunrui Li ,  Chi Cao Minh ,  Wilson Chan ,  Tolga Yurek ,  Ping-Hsiu Hsieh

IPC: G06F11/14 ,  G06F17/30

CPC classification number: G06F17/30557 ,  G06F17/30

Abstract: Embodiment provide that each pluggable database (PDB) in a container database is associated with a distinct distributed lock manager (DLM) domain. Thus, in order to access a PDB, a database server instance joins the DLM domain for the PDB. To perform actions on the PDB, the instance secures locks that belong to the DLM domain for the particular PDB. As such, buffers storing data for the PDB may be managed separately from buffers storing data for other PDBs using the PDB-specific DLM domains. An instance forcefully closing a particular PDB marks the DLM domain of the PDB as invalid, which allows detection of the forceful closure by a recovery instance. Detection of an invalid DLM domain by an instance causes the instance to automatically recover the PDB by accessing pertinent ranges of redo logs and replaying changes made to data blocks for the PDB indicated in the logs.

公开(公告)号：US09684566B2

公开(公告)日：2017-06-20

申请号：US14135202

申请日：2013-12-19

Applicant: Oracle International Corporation

Inventor： Yunrui Li ,  Chi Cao Minh ,  Kumar Rajamani ,  Jaebock Lee ,  Sanket Jain ,  Giridhar Ravipati ,  Jonghyun Lee

IPC: G06F17/30 ,  G06F11/14

CPC classification number: G06F3/0619 ,  G06F3/065 ,  G06F3/067 ,  G06F11/1448 ,  G06F11/1469 ,  G06F11/1471 ,  G06F12/084 ,  G06F13/1663 ,  G06F17/30289 ,  G06F17/30292 ,  G06F17/3048 ,  G06F17/30557 ,  G06F17/30566 ,  G06F17/30595 ,  G06F17/30867 ,  G06F21/6218 ,  G06F2201/80 ,  G06F2201/835 ,  G06F2212/60 ,  G06F2212/62

Abstract: A container database stores redo records and logical timestamps for multiple pluggable databases. When it is detected that a first read-write instance of the pluggable database is opened and no other read-write instances of the pluggable database are open, offline range data associated with the pluggable database is updated. When it is detected that a second read-write instance of the pluggable database is closed, and the second read-write instance is the last open read-write instance, the offline range data associated with the pluggable database is updated. The pluggable database is restored to a logical timestamp associated with a restore request based on the offline range data.