公开(公告)号：US10353895B2

公开(公告)日：2019-07-16

申请号：US14961309

申请日：2015-12-07

Applicant: SAP SE

Inventor： Changgyoo Park ,  Yongjae Chuh ,  Juchang Lee ,  Norman May ,  Thomas Seufert ,  Hannes Jakschitsch

IPC: G06F16/00 ,  G06F16/2453 ,  G06F16/22 ,  G06F16/23 ,  G06F16/2455

Abstract: Disclosed herein are systems, methods, and computer program products for providing transaction-consistent snapshots of data stored in or associated with a database. An embodiment operates by receiving, at a source database, an update request to update data associated with a table stored at the source database, and modifying a value of a modification-in-progress data structure corresponding to the table to indicate that a modification is in progress for the table. The embodiment includes updating a value of a commit identification counter and a table time stamp associated with the table to indicate that cached data having a time stamp older than the updated time stamp are invalid. The embodiment further includes modifying the value of the modification-in-progress counter to indicate completion of table modification.

公开(公告)号：US10275508B2

公开(公告)日：2019-04-30

申请号：US14946757

申请日：2015-11-19

Applicant: SAP SE

Inventor： Christian Bensberg ,  Norman May ,  Alexander Boehm ,  Juchang Lee ,  Sung Heun Wi ,  Jeong Ae Han ,  Ki Hong Kim ,  Kyu Hwan Kim ,  Chul Won Lee ,  Andreas Kemmler ,  Christoph Glania ,  Armin Risch ,  Kai Morich

IPC: G06F17/30

Abstract: A method may include receiving a query for data to be provided by a database server, wherein the query includes an indication of a maximum lag. The method may further include determining whether a hint is available to apply to the query, wherein the hint affects an execution of the query. When no hint is available, a baseline database server may be selected to be the database server. When the hint is available, a replication server or a cache server may be selected to be the database server based on the hint and the maximum lag. The query may be processed at the selected database server.

公开(公告)号：US10235440B2

公开(公告)日：2019-03-19

申请号：US14977427

申请日：2015-12-21

Applicant: SAP SE

Inventor： Juchang Lee ,  Chang Gyoo Park ,  Kyu Hwan Kim

IPC: G06F17/30

Abstract: Technologies are described for facilitating transaction processing within a database environment having first, second, and third database system nodes. In the database system, the first database system node receives from the second database system node a request to precommit a first database transaction. The first database system node stores information for the first database transaction that includes an indication that the second database system node coordinates the committing of the first database transaction. The first database system node receives from the third database system node a request to precommit a second database transaction. The first database system node stores information for the second database transaction that includes an indication that the third database system node coordinates the committing of the second database transaction.

公开(公告)号：US10185632B2

公开(公告)日：2019-01-22

申请号：US14657865

申请日：2015-03-13

Applicant: SAP SE

Inventor： Juchang Lee ,  Joo-Yeon Lee ,  Kyu-Hwan Kim ,  Deok-Hoe Kim ,  Kyungyul Park

IPC: G06F17/30 ,  G06F11/14

Abstract: Disclosed herein are system, method, and computer program product embodiments for minimizing table lock duration during lost change resynchronization between a source table and a replica table. An embodiment operates by detecting a restart at a source node or a replica node. A source table at the source node is then locked based on the detection. A database transaction is then created for a lost change resynchronization operation and the source table is unlocked. The database transaction is then compared to another database transaction based on its timestamp. Based on the comparison, either the database transaction for the lost change resynchronization operation or the other database transaction is executed.

公开(公告)号：US20180336258A1

公开(公告)日：2018-11-22

申请号：US15601008

申请日：2017-05-22

Applicant: SAP SE

Inventor： Juchang Lee ,  Chang Gyoo Park ,  Hyejeong Lee ,  Kyu Hwan Kim ,  Mihnea Andrei

IPC: G06F17/30

CPC classification number: G06F16/273 ,  G06F11/36 ,  G06F16/219 ,  G06F16/2358 ,  G06F16/2379 ,  G06F16/2455

Abstract: An oldest version timestamp is received from a first database. A current commit timestamp is received from a second database configured to asynchronously replicate the first database. The current global commit timestamp corresponds to a commit transaction executed in the first database and subsequently replicated in the second database. A first test query is then issued to the second database including a request for a current timestamp of the second database. A second test query is issued to the primary database requesting records associated with a target update version that has a target timestamp equal to the current snapshot timestamp. A determination is then made that a first return associated with the first test query and a second return associated with the second test query are identical indicating a successful validation. Related apparatus, systems, techniques and articles are also described.

公开(公告)号：US10095764B2

公开(公告)日：2018-10-09

申请号：US14871675

申请日：2015-09-30

Applicant: SAP SE

Inventor： Chang Gyoo Park ,  Juchang Lee ,  Kyu Hwan Kim ,  Hyoung Jun Na ,  Hyejeong Lee

IPC: G06F17/30 ,  G06F11/14

Abstract: Technologies are described for performing replication within a database environment. Where a database transaction is replicated at multiple replica nodes, a replica node is selected as a coordinator replica node for the transaction. The other replica node or nodes are designated as follower replica nodes for the transaction. A follower replica node sends the coordinator replica node a precommit notification when the follower replica node has precommitted the transaction. The coordinator replica node sends the follower replica node a postcommit notification to commit the transaction when the transaction has been precommitted by all of the replica nodes to which the transaction is to be replicated.

公开(公告)号：US20170357576A1

公开(公告)日：2017-12-14

申请号：US15231566

申请日：2016-08-08

Applicant: SAP SE

Inventor： Juchang Lee ,  Chang Gyoo Park ,  Jaeyun Noh ,  Sung Heun Wi

IPC: G06F12/02

CPC classification number: G06F12/0253 ,  G06F3/0619 ,  G06F3/0641 ,  G06F3/065 ,  G06F3/067 ,  G06F12/0261 ,  G06F12/0269 ,  G06F16/2322 ,  G06F16/2329 ,  G06F2212/1044 ,  G06F2212/702

Abstract: Technologies for performing garbage collection in database systems, such as multi-version concurrency control (MVCC) database systems, are described. For example, different garbage collection techniques can be used separately or in various combinations, including interval garbage collection, group garbage collection, table garbage collection, and combinations. For example, a particular type of combination, called hybrid garbage collection, uses technique from interval garbage collection and group garbage collection, or from interval, group, and table garbage collection.

公开(公告)号：US09594799B2

公开(公告)日：2017-03-14

申请号：US14827236

申请日：2015-08-14

Applicant: SAP SE

Inventor： Franz Faerber ,  Juchang Lee ,  Ivan Schreter

IPC: G06F7/00 ,  G06F17/00 ,  G06F17/30 ,  G06F3/06

CPC classification number: G06F17/30371 ,  G06F3/0604 ,  G06F3/0638 ,  G06F3/0644 ,  G06F3/0647 ,  G06F3/065 ,  G06F3/0652 ,  G06F3/0673 ,  G06F3/0683 ,  G06F17/30117 ,  G06F17/30153 ,  G06F17/30315 ,  G06F17/30348 ,  G06F17/30377 ,  G06F17/30575 ,  G06F17/30587

Abstract: A system and method of logless atomic data movement. An internal transaction is started within a multi-level storage architecture, the internal transaction to merge data from the first level storage structure to the second level storage structure. Committed data is read from a first level storage structure of the multi-level storage architecture as specified by the internal transaction. The committed data from the first level storage structure is inserted into a second level storage structure in a bulk insertion process, and the committed data is marked as being deleted from the first level storage. The internal transaction is then committed to the multi-level storage architecture when the committed data has been inserted into the second level storage structure.

Abstract translation: 无原子数据运动的系统和方法。 内部事务在多级存储架构内启动，内部事务将数据从第一级存储结构合并到第二级存储结构。 从内部事务指定的多级存储架构的第一级存储结构读取提交的数据。 来自第一级存储结构的提交的数据被插入到批量插入过程中的第二级存储结构中，并且所提交的数据被标记为从第一级存储中被删除。 当提交的数据已插入到第二级存储结构中时，内部事务将被提交到多级存储架构。

公开(公告)号：US20160371356A1

公开(公告)日：2016-12-22

申请号：US14866449

申请日：2015-09-25

Applicant: SAP SE

Inventor： Juchang Lee ,  Chang Gyoo Park ,  Kyu Hwan Kim ,  Deok Koo Kim

IPC: G06F17/30

CPC classification number: G06F17/30578 ,  G06F17/30377

Abstract: Technologies are described for facilitating transaction processing within a database environment having a coordinator node, a first worker node, and at least a second worker node. The first worker node sends a request from to the coordinator node for at least a first synchronization token maintained by the coordinator node. The first worker node receives the at least a first synchronization token from the coordinator node. The first worker node assigns the at least a first synchronization token to a snapshot as a snapshot ID value. The snapshot is executed at the first worker node. The first worker node forwards the snapshot ID value to the at least a second worker node.

Abstract translation: 描述了用于促进具有协调器节点，第一工作者节点和至少第二工作节点的数据库环境内的事务处理的技术。 第一工作节点向协调器节点发送至少由协调器节点维护的第一同步令牌的请求。 第一工作节点从协调器节点接收至少一个第一同步令牌。 第一个工作节点将至少一个第一同步令牌分配给快照作为快照ID值。 快照在第一个工作节点执行。 第一个工作节点将快照ID值转发到至少第二个工作节点。

公开(公告)号：US11874746B2

公开(公告)日：2024-01-16

申请号：US16944015

申请日：2020-07-30

Applicant: SAP SE

Inventor： Christian Bensberg ,  Steffen Geissinger ,  Juchang Lee ,  Chang Gyoo Park ,  Kyu Hwan Kim ,  Deok Koo Kim

IPC: G06F11/14

CPC classification number: G06F11/1464 ,  G06F2201/87

Abstract: Technologies are described for facilitating database system recovery in a distributed database environment having a master node and at least one slave node. The master node maintains an in-memory reference that includes transaction identifiers and their corresponding commit identifiers. When a slave node requests that a commit identifier be assigned to a transaction, the transaction and commit identifiers for the transaction are added to the in-memory reference. The commit identifier is sent by the master node to the slave node. The slave node writes a log entry to a commit log that includes the transaction identifier and the assigned commit identifier. If the database system is interrupted before the slave node writes the commit log entry, the slave node can request the commit identifier for the transaction from the master node, which retrieves the identifier from the in-memory reference.