公开(公告)号：US20240086386A1

公开(公告)日：2024-03-14

申请号：US17940904

申请日：2022-09-08

Applicant: SAP SE

Inventor： Hans-Joerg Leu ,  Dan Ding ,  Srinivas Gajjalakonda ,  Fei Qiu ,  Carsten Mueller ,  Alexander Schroeder

IPC: G06F16/22 ,  G06F16/27

CPC classification number: G06F16/2282 ,  G06F16/273 ,  G06F16/278

Abstract: The present disclosure provides more efficient techniques for removing a host from a multi-host database system. An instruction to remove a host system may be received. In response, a determination of whether the first host system does or does not store any source tables is made based on a host-type identifier for the host system. This determination may not require obtaining landscape information for each of the hosts in the database system. If the host system stores replica tables and does not store source tables, those replica tables may be dropped based on the determination that the first host system does not store any source tables. As such, in cases where table redistribution is not needed the landscape information is not obtained, thereby making the host removal process more efficient.

公开(公告)号：US11899645B1

公开(公告)日：2024-02-13

申请号：US17942035

申请日：2022-09-09

Applicant: SAP SE

Inventor： Fei Qiu ,  Hans-Joerg Leu ,  Srinivas Gajjalakonda ,  Dan Ding

IPC: G06F16/22 ,  G06F16/21 ,  G06F16/23 ,  G06F16/27

CPC classification number: G06F16/2282 ,  G06F16/211 ,  G06F16/2379 ,  G06F16/27

Abstract: A two phase move technique for moving groups of tables may reduce cross-host communication and length of table locks. A group including a first table and a second table may be moved to the destination host system. This is done by creating a third table replicating the first table and creating a fourth table replicating the second table on the destination host, and replicas of other tables in the group. The tables in the group are not locked against modifications during the creation of the replica tables. After the creation of the replicas, roles of the original tables and the created tables are switched such that the original tables are set to the replica role and the created tables stored on the destination are set to the source role. The original tables are dropped after the switching of the roles.

公开(公告)号：US20250005078A1

公开(公告)日：2025-01-02

申请号：US18343938

申请日：2023-06-29

Applicant: SAP SE

Inventor： Norman May ,  Dan Ding ,  Zhe Qu ,  Fei Qiu

IPC: G06F16/903

Abstract: Methods, systems, and computer-readable storage media for receiving, from a database client, an asynchronous lookup request including a key representative of a query and, in response, returning a value handle including a value promise, receiving, from the database client, a get request based on the value promise, determining that a query result corresponding to the key is unavailable in a results cache and that the key is in an unlocked state, and in response, returning a null pointer and a first key lock status to the first database client, receiving, from the database client, a key, value pair including the key and a value, the value comprising the query result, and storing the key, value pair in the results cache.