公开(公告)号：US10990610B2

公开(公告)日：2021-04-27

申请号：US16376963

申请日：2019-04-05

Applicant: SAP SE

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

IPC: G06F17/00 ,  G06F16/27 ,  G06F16/28 ,  G06F16/951 ,  G06F16/23 ,  G06F16/2458 ,  G06F11/14

Abstract: Technologies are described for performing synchronization within a database environment. A source host stores multiple database tables and a replica host stores copies of the multiple database tables. During synchronization, replication log replay is blocked at the replica node, and a multithreaded process locks the multiple database tables of the source hosts, reactivates replication log generation for each of the multiple database tables, and then unlocks the database tables. A synchronization timestamp is acquired and used to synchronize the multiple database tables with the copies of the multiple database tables. After synchronization, replication log replay is reactivated at the replica host for the copies of the multiple database tables.

公开(公告)号：US20210089550A1

公开(公告)日：2021-03-25

申请号：US16713850

申请日：2019-12-13

Applicant: SAP SE

Inventor： Ruediger Karl ,  Mihnea Andrei ,  Juchang Lee ,  Stefan Baeuerle ,  Seyeong Bae ,  Joo Yeon Lee

IPC: G06F16/25 ,  G06F16/22 ,  G06F16/2455 ,  G06F16/21 ,  G06F16/23

Abstract: Techniques and solutions are described for implementing virtual table schemas. A virtual table schema includes a logical pointer that is used to target a table that includes data and is defined according to the virtual table schema. Values assigned to the logical pointer can be used to target tables at different locations, such as in a federated database system or in a cache of a database management system of a central computing system. When data associated with the virtual table is requested, or prior to receiving the request, the data can be stored in a table in the cache. The logical pointer can be updated to reference the cache. If the cache is full, the table can be removed from the cache, and the logical pointer can be updated to reference a table at the federated database system.

公开(公告)号：US10824611B2

公开(公告)日：2020-11-03

申请号：US16027897

申请日：2018-07-05

Applicant: SAP SE

Inventor： Juchang Lee ,  KiYong Lee ,  Nosub Sung

IPC: G06F16/20 ,  G06F16/22 ,  G06F16/27 ,  G06F16/23 ,  G06F16/2455

Abstract: Improvements to the performance of distributed database systems are described. Suggested table distributions are provided that can reduce the performance overhead associated with database operations that involve multiple nodes, and can provide more even distribution of computing resource use. A method includes minimizing a cost function that includes a plurality of performance metrics, at least a portion of the metrics being associated with a weight. Candidate table distributions can be analyzed in an iterative manner to determine a lowest-cost distribution. A final table distribution can be output, such as to a user.

公开(公告)号：US10761946B2

公开(公告)日：2020-09-01

申请号：US15430091

申请日：2017-02-10

Applicant: SAP SE

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

IPC: G06F11/14

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.

公开(公告)号：US10664497B2

公开(公告)日：2020-05-26

申请号：US15380720

申请日：2016-12-15

Applicant: SAP SE

Inventor： Yongsik Yoon ,  Chanho Jeong ,  Juchang Lee ,  Chang Bin Song ,  Yong Sik Kwon ,  Sang Kyun Cha

IPC: G06F16/22 ,  G06F16/28 ,  G06F16/27 ,  G06F16/9535 ,  G06F40/177 ,  G06F16/23

Abstract: A hybrid database table is stored as both a row and a column store. One or more techniques may be employed alone or in combination to enhance performance of the hybrid table by regulating access to, and/or the size of, the processing-intensive column store data. For example during an insert operation, the column store data may be searched for a uniqueness violation only after certain filtering and/or boundary conditions have been considered. In another technique, a hybrid table manager may control movement of data to the column store based upon considerations such as frequency of access, or underlying business logic. In still another technique, querying of the hybrid table may result in a search of the column store data only after an initial search of row store data fails to return a result.

公开(公告)号：US10554771B2

公开(公告)日：2020-02-04

申请号：US16362286

申请日：2019-03-22

Applicant: SAP SE

Inventor： Chang Gyoo Park ,  Juchang Lee ,  Kyu Hwan Kim ,  Chul Won Lee ,  Myunggon Park ,  Eunjin Song ,  Nosub Sung

IPC: H04L29/06 ,  H04L29/08 ,  G06F16/20 ,  G06F16/2455 ,  H04L12/747

Abstract: Technologies are described for facilitating replay of requests for database operations. A plurality of requests for database operations are received. Each of the plurality of requests includes a type, an access unit identifier, and a chronological identifier. Execution dependencies are determined between the plurality of requests based on the type, access unit identifier, and chronological identifier of each of the plurality of requests. The execution dependencies are stored.

公开(公告)号：US10534764B2

公开(公告)日：2020-01-14

申请号：US15261188

申请日：2016-09-09

Applicant: SAP SE

Inventor： Franz Faerber ,  Juchang Lee ,  Ivan Schreter

IPC: G06F7/00 ,  G06F17/00 ,  G06F16/22 ,  G06F16/28 ,  G06F16/2455

Abstract: A multi-level storage architecture and method of performing a partial merge are disclosed. A main store is partitioned into a passive main part and an active main part, the active main part being empty at a start of the partial merge, the passive main part storing encoded data records of the main store that are not subject to the partial merge. A values index corresponding to a sorted dictionary of the passive main part is set to a cardinality of n. The data records of a second level storage structure is merged into the active main part, the active main part having a dictionary that starts with a value of n+1, such that the merging into the active main part continues an encoding scheme according to the values index of the passive main part.

公开(公告)号：US20200012734A1

公开(公告)日：2020-01-09

申请号：US16027897

申请日：2018-07-05

Applicant: SAP SE

Inventor： Juchang Lee ,  KiYong Lee ,  Nosub Sung

IPC: G06F17/30

Abstract: Technologies are described for improving the performance of distributed database systems. The technologies provide suggested table distributions that can reduce the performance overhead associated with database operations that involve multiple nodes, and can provide more even distribution of computing resource use. In a particular example, a method includes minimizing a scoring function that includes a plurality of performance metrics, at least a portion of the metrics being associated with a weight. Candidate table distributions can be analyzed in an iterative manner to determine a lowest-score distribution. A final table distribution can be output, such as to a user.

公开(公告)号：US20190303470A1

公开(公告)日：2019-10-03

申请号：US15944429

申请日：2018-04-03

Applicant: SAP SE

Inventor： Juchang Lee ,  Chang Gyoo Park ,  Hyoung Jun Na

IPC: G06F17/30

Abstract: Techniques are described for use in database and data management systems to efficiently capture and replicate changes that occur in database tables. The changes are captured in a transaction-consistent order, and in a format that may easily be searched and accessed using common relational queries.

公开(公告)号：US10360146B2

公开(公告)日：2019-07-23

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 ,  G06F16/23 ,  G06F3/06 ,  G06F3/05

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.