Patents by Inventor Deok-Hoe Kim
Deok-Hoe Kim has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11914572Abstract: Technologies are described providing adaptive query routing in a replicated database environment. The technologies can be used with a variety of replication protocols. Prepared statements, such as for queries, from a database client can be routed to a source node, or a source node and available replica nodes, when a replica node becomes unavailable. When a replica node becomes available again, a prepared statement can be updated to indicate that the updated prepared statement can be executed at nodes including the replica node that is available again. Prepared statement routing can also be used when a portion of replicated data becomes unavailable at a replica node, but a portion of replicated data remains available.Type: GrantFiled: December 22, 2022Date of Patent: February 27, 2024Assignee: SAP SEInventors: Juchang Lee, Kyu Hwan Kim, Joo Yeon Lee, Kyungyul Park, Deok Hoe Kim
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Publication number: 20230129099Abstract: Technologies are described providing adaptive query routing in a replicated database environment. The technologies can be used with a variety of replication protocols. Prepared statements, such as for queries, from a database client can be routed to a source node, or a source node and available replica nodes, when a replica node becomes unavailable. When a replica node becomes available again, a prepared statement can be updated to indicate that the updated prepared statement can be executed at nodes including the replica node that is available again. Prepared statement routing can also be used when a portion of replicated data becomes unavailable at a replica node, but a portion of replicated data remains available.Type: ApplicationFiled: December 22, 2022Publication date: April 27, 2023Applicant: SAP SEInventors: Juchang Lee, Kyu Hwan Kim, Joo Yeon Lee, Kyungyul Park, Deok Hoe Kim
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Patent number: 11599543Abstract: Technologies are described for routing structured query language (SQL) statements to elastic compute nodes (ECNs) using workload classes within a distributed database environment. The elastic compute nodes do not store persistent database tables. For example, a SQL statement can be received for execution within the distributed database environment. A workload class can be identified that matches properties of the SQL statement. Based on the workload class, a routing location hint can be obtained that identifies a set of elastic compute nodes. The SQL statement can then be routed to one of the identified elastic compute nodes for execution. Execution of the SQL statement at the elastic compute node can involve retrieving database data from other nodes which store persistent database tables.Type: GrantFiled: May 26, 2022Date of Patent: March 7, 2023Assignee: SAP SEInventors: Jaeyoung Choi, Deok Hoe Kim, Kyu Hwan Kim, Chae Kwang Lee, Jane Jung Lee, Juchang Lee
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Patent number: 11573947Abstract: Technologies are described providing adaptive query routing in a replicated database environment. The technologies can be used with a variety of replication protocols. Prepared statements, such as for queries, from a database client can be routed to a source node, or a source node and available replica nodes, when a replica node becomes unavailable. When a replica node becomes available again, a prepared statement can be updated to indicate that the updated prepared statement can be executed at nodes including the replica node that is available again. Prepared statement routing can also be used when a portion of replicated data becomes unavailable at a replica node, but a portion of replicated data remains available.Type: GrantFiled: May 8, 2017Date of Patent: February 7, 2023Assignee: SAP SEInventors: Juchang Lee, Kyu Hwan Kim, Joo Yeon Lee, Kyungyul Park, Deok Hoe Kim
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Publication number: 20220318249Abstract: Technologies are described for routing structured query language (SQL) statements to elastic compute nodes (ECNs) using workload classes within a distributed database environment. The elastic compute nodes do not store persistent database tables. For example, a SQL statement can be received for execution within the distributed database environment. A workload class can be identified that matches properties of the SQL statement. Based on the workload class, a routing location hint can be obtained that identifies a set of elastic compute nodes. The SQL statement can then be routed to one of the identified elastic compute nodes for execution. Execution of the SQL statement at the elastic compute node can involve retrieving database data from other nodes which store persistent database tables.Type: ApplicationFiled: May 26, 2022Publication date: October 6, 2022Applicant: SAP SEInventors: Jaeyoung Choi, Deok Hoe Kim, Kyu Hwan Kim, Chae Kwang Lee, Jane Jung Lee, Juchang Lee
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Patent number: 11379323Abstract: A computer implemented method is provided for determining a delay between a first database and an associated replicated database by replicating transactions of the first database in the replicated database, determining a delay between the two databases based on a commit timestamp from the first database and a timestamp associated with the commit transaction becoming visible in the replicated database. Then, after a predefined period of time has elapsed since replicating the commit transaction, determining a second delay based on a timestamp associated with a heartbeat log and a replicated database system time. And, selectively determining to execute or deny a statement received by the replicated database based on the second delay. Related apparatus, systems, techniques and articles are also described.Type: GrantFiled: December 5, 2019Date of Patent: July 5, 2022Assignee: SAP SEInventors: Kyu Hwan Kim, Deok Hoe Kim, Beomsoo Kim, Juchang Lee, Werner Thesing, Christoph Roterring
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Patent number: 11379483Abstract: Technologies are described for routing structured query language (SQL) statements to elastic compute nodes (ECNs) using workload classes within a distributed database environment. The elastic compute nodes do not store persistent database tables. For example, a SQL statement can be received for execution within the distributed database environment. A workload class can be identified that matches properties of the SQL statement. Based on the workload class, a routing location hint can be obtained that identifies a set of elastic compute nodes. The SQL statement can then be routed to one of the identified elastic compute nodes for execution. Execution of the SQL statement at the elastic compute node can involve retrieving database data from other nodes which store persistent database tables.Type: GrantFiled: March 30, 2021Date of Patent: July 5, 2022Assignee: SAP SEInventors: Jaeyoung Choi, Deok Hoe Kim, Kyu Hwan Kim, Chae Kwang Lee, Jane Jung Lee, Juchang Lee
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Patent number: 10860612Abstract: Disclosed herein are system, method, and computer readable device embodiments for parallel replication of databases across row-store and column-store table formats. An embodiment operates by maintaining a replication log and a storage-level recovery log formatted according to separate respective log formats, logging a record-level SQL execution result, and replicating at least one database table from a primary server to at least one replica server. The primary server and the at least one replica server may each be configured to store data according to one table format of a row-store table format and a column-store table format, such that the primary server's table format is different from the at least one replica server's table format.Type: GrantFiled: June 21, 2018Date of Patent: December 8, 2020Assignee: SAP SEInventors: Juchang Lee, Hyoung Jun Na, Kyu Hwan Kim, Deok Hoe Kim, Chang Gyoo Park
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Publication number: 20200110674Abstract: A computer implemented method is provided for determining a delay between a first database and an associated replicated database by replicating transactions of the first database in the replicated database, determining a delay between the two databases based on a commit timestamp from the first database and a timestamp associated with the commit transaction becoming visible in the replicated database. Then, after a predefined period of time has elapsed since replicating the commit transaction, determining a second delay based on a timestamp associated with a heartbeat log and a replicated database system time. And, selectively determining to execute or deny a statement received by the replicated database based on the second delay. Related apparatus, systems, techniques and articles are also described.Type: ApplicationFiled: December 5, 2019Publication date: April 9, 2020Inventors: Kyu Hwan Kim, Deok Hoe Kim, Beomsoo Kim, Juchang Lee, Werner Thesing, Christoph Roterring
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Patent number: 10534676Abstract: A computer implemented method is provided for determining a delay between a first database and an associated replicated database by replicating transactions of the first database in the replicated database, determining a delay between the two databases based on a commit timestamp from the first database and a timestamp associated with the commit transaction becoming visible in the replicated database. Then, after a predefined period of time has elapsed since replicating the commit transaction, determining a second delay based on a timestamp associated with a heartbeat log and a replicated database system time. And, selectively determining to execute or deny a statement received by the replicated database based on the second delay. Related apparatus, systems, techniques and articles are also described.Type: GrantFiled: February 27, 2017Date of Patent: January 14, 2020Assignee: SAP SEInventors: Kyu Hwan Kim, Deok Hoe Kim, Beomsoo Kim, Juchang Lee, Werner Thesing, Christoph Roterring
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Publication number: 20190325055Abstract: Disclosed herein are system, method, and computer readable device embodiments for parallel replication of databases across row-store and column-store table formats. An embodiment operates by maintaining a replication log and a storage-level recovery log formatted according to separate respective log formats, logging a record-level SQL execution result, and replicating at least one database table from a primary server to at least one replica server. The primary server and the at least one replica server may each be configured to store data according to one table format of a row-store table format and a column-store table format, such that the primary server's table format is different from the at least one replica server's table format.Type: ApplicationFiled: June 21, 2018Publication date: October 24, 2019Inventors: Juchang LEE, Hyoung Jun NA, Kyu Hwan KIM, Deok Hoe KIM, Chang Gyoo PARK
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Patent number: 10185632Abstract: 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.Type: GrantFiled: March 13, 2015Date of Patent: January 22, 2019Assignee: SAP SEInventors: Juchang Lee, Joo-Yeon Lee, Kyu-Hwan Kim, Deok-Hoe Kim, Kyungyul Park
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Publication number: 20180322157Abstract: Technologies are described providing adaptive query routing in a replicated database environment. The technologies can be used with a variety of replication protocols. Prepared statements, such as for queries, from a database client can be routed to a source node, or a source node and available replica nodes, when a replica node becomes unavailable. When a replica node becomes available again, a prepared statement can be updated to indicate that the updated prepared statement can be executed at nodes including the replica node that is available again. Prepared statement routing can also be used when a portion of replicated data becomes unavailable at a replica node, but a portion of replicated data remains available.Type: ApplicationFiled: May 8, 2017Publication date: November 8, 2018Applicant: SAP SEInventors: Juchang Lee, Kyu Hwan Kim, Joo Yeon Lee, Kyungyul Park, Deok Hoe Kim
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Publication number: 20180246928Abstract: A computer implemented method is provided for determining a delay between a first database and an associated replicated database by replicating transactions of the first database in the replicated database, determining a delay between the two databases based on a commit timestamp from the first database and a timestamp associated with the commit transaction becoming visible in the replicated database. Then, after a predefined period of time has elapsed since replicating the commit transaction, determining a second delay based on a timestamp associated with a heartbeat log and a replicated database system time. And, selectively determining to execute or deny a statement received by the replicated database based on the second delay. Related apparatus, systems, techniques and articles are also described.Type: ApplicationFiled: February 27, 2017Publication date: August 30, 2018Inventors: Kyu Hwan Kim, Deok Hoe Kim, Beomsoo Kim, Juchang Lee, Werner Thesing, Christoph Roterring
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Patent number: 9965359Abstract: Disclosed herein are system, method, and computer program product embodiments for removing a deadlock during replication from distributed source tables to a replica node. An embodiment operates by detecting a deadlock at a parallel log replayer at a replica node. A first replication log entry from a queue at the parallel log replayer is then selected based on whether removing the first replication log entry from the queue removes the deadlock. The first replication log entry is then forwarded to a waiting queue. A second replication log entry is then replayed at the parallel log replayer. After replaying the second replication log entry, the first replication log entry is replayed at the parallel log replayer.Type: GrantFiled: March 13, 2015Date of Patent: May 8, 2018Assignee: SAP SEInventors: Juchang Lee, Chang-Gyoo Park, Hyoung-Jun Na, Deok-Hoe Kim
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Publication number: 20160147858Abstract: Disclosed herein are system, method, and computer program product embodiments for removing a deadlock during replication from distributed source tables to a replica node. An embodiment operates by detecting a deadlock at a parallel log replayer at a replica node. A first replication log entry from a queue at the parallel log replayer is then selected based on whether removing the first replication log entry from the queue removes the deadlock. The first replication log entry is then forwarded to a waiting queue. A second replication log entry is then replayed at the parallel log replayer. After replaying the second replication log entry, the first replication log entry is replayed at the parallel log replayer.Type: ApplicationFiled: March 13, 2015Publication date: May 26, 2016Inventors: Juchang Lee, Chang-Gyoo Park, Hyoung-Jun Na, Deok-Hoe Kim