US 12,079,205 B2
Snapshot isolation query transactions in distributed systems
Sarvesh Singh, Issaquah, WA (US); Xianfei Deng, Redmond, WA (US); Hari Krishna Sunder, Redmond, WA (US); Sandeep Lingam, Redmond, WA (US); and Srikumar Rangarajan, Sammamish, WA (US)
Assigned to MICROSOFT TECHNOLOGY LICENSING, LLC, Redmond, WA (US)
Filed by Microsoft Technology Licensing, LLC, Redmond, WA (US)
Filed on Jun. 5, 2023, as Appl. No. 18/328,992.
Application 18/328,992 is a continuation of application No. 17/207,282, filed on Mar. 19, 2021, abandoned.
Prior Publication US 2023/0315721 A1, Oct. 5, 2023
Int. Cl. G06F 16/00 (2019.01); G06F 16/215 (2019.01); G06F 16/23 (2019.01); G06F 16/2455 (2019.01); G06F 16/27 (2019.01)
CPC G06F 16/2379 (2019.01) [G06F 16/215 (2019.01); G06F 16/2343 (2019.01); G06F 16/2455 (2019.01); G06F 16/27 (2019.01)] 20 Claims
OG exemplary drawing
 
1. A system, comprising:
a processor;
a computer-readable storage medium comprising program instructions that, when executed by the processor, cause the processor to:
receive a periodic heartbeat communication comprising:
an oldest local query identifier of queries that are active, and
a system activity list comprising active identifiers of data-modifying transactions;
store, in a table, the system activity list and commit identifiers of data-modifying transactions that are successfully completed;
determine a global oldest active transaction identifier based at least on the periodic heartbeat communication; and
initiate a cleanup operation on items determined based on the commit identifiers that are older than the global oldest transaction identifier and older than a point-in-time retention interval.