公开(公告)号：US20230315720A1

公开(公告)日：2023-10-05

申请号：US18326356

申请日：2023-05-31

Applicant: Snowflake Inc.

Inventor： Chen Luo ,  Alexander Miller ,  William Waddington ,  Zhaohui Zhang

IPC: G06F16/23 ,  G06F9/52

CPC classification number: G06F16/2379 ,  G06F9/524 ,  G06F16/2365

Abstract: The subject technology determines that a first visible version of a key is not one of a N number of newest versions of the key based on searching for the key in a regular space to locate the first visible version of the key. The subject technology performs a search of an undo space to locate a second visible version of the key. The subject technology determines whether the first visible version or the second visible version of the key is newer. The subject technology provides a newer version of the key between the first visible version and the second visible version of the key.

公开(公告)号：US11704305B1

公开(公告)日：2023-07-18

申请号：US17649737

申请日：2022-02-02

Applicant: Snowflake Inc.

Inventor： Chen Luo ,  Alexander Miller ,  William Waddington ,  Zhaohui Zhang

IPC: G06F16/23 ,  G06F9/52

CPC classification number: G06F16/2379 ,  G06F9/524 ,  G06F16/2365

Abstract: The subject technology performs a search for a key in a regular space to locate a first visible version of the key. The subject technology determines that the first visible version of the key is not one of a N number of newest versions of the key. The subject technology performs a search of an undo space to locate a second visible version of the key. The subject technology determines whether the first visible version or the second visible version of the key is newer. The subject technology provides a newer version of the key between the first visible version and the second visible version of the key.

公开(公告)号：US20220350677A1

公开(公告)日：2022-11-03

申请号：US17647752

申请日：2022-01-12

Applicant: Snowflake Inc.

Inventor： Chen Luo ,  Alexander Miller ,  William Waddington

IPC: G06F9/52 ,  G06F16/25 ,  G06F16/23

Abstract: The subject technology performs a locking operation on a first set of keys by a first statement of a first transaction. The subject technology determines that a conflict occurred between the first statement and a second transaction. The subject technology determines that the second transaction has yet to complete after a predetermined period of time. The subject technology performs a deadlock detection process where the subject technology stores a key and value in a table indicating the first transaction and the second transaction, detects, based at least in part on a graph traversal of the table starting from the first transaction, a cycle between the first transaction and the second transaction, and determines that the first transaction is a youngest transaction in the detected cycle. The subject technology ceases execution of the first transaction in response to the first transaction being a youngest transaction in a detected cycle.

公开(公告)号：US11436212B2

公开(公告)日：2022-09-06

申请号：US17454368

申请日：2021-11-10

Applicant: Snowflake Inc.

Inventor： Chen Luo ,  Alexander Miller ,  William Waddington ,  Zhaohui Zhang

IPC: G06F16/23

Abstract: The subject technology inserts, by a first transaction, a new version of an object, the inserting corresponding to a first statement from the first transaction, the first statement including information indicating a first key, a first transaction identifier, a first statement number, and a first restart count. The subject technology performs, by a second transaction, a range read, the range read including information indicating the first key. The subject technology receives, after performing the range read, a set of conflicting transactions. The subject technology determines that a conflict occurred between the first transaction and a third transaction from the set of conflicting transactions.