公开(公告)号：US09747310B2

公开(公告)日：2017-08-29

申请号：US13909928

申请日：2013-06-04

Applicant: Google Inc.

Inventor： Wilson Cheng-Yi Hsieh ,  Alexander Lloyd ,  Eric Hugh Veach

IPC: G06F7/00 ,  G06F17/30

CPC classification number: G06F17/30292 ,  G06F17/30353 ,  G06F17/30356

Abstract: A method reads and writes data from a database table. Each row in the table has a primary key and multiple non-key columns. Each non-key column has one or more column values, and each column value has an associated timestamp that identifies when the column value was stored. The timestamps associated with the column values in each non-key column provide a unique order for the column values. A read transaction is initiated to read from a first non-key column of a first row. A write transaction is in progress that is updating a second non-key column of the first row, where the second non-key column is distinct from the first non-key column. The write transaction holds a lock on the second non-key column of the first row. The method concurrently reads the data from the first non-key column and writes a new column value to the second non-key column.

公开(公告)号：US10783133B1

公开(公告)日：2020-09-22

申请号：US15631646

申请日：2017-06-23

Applicant: Google Inc.

Inventor： Wilson Cheng-Yi Hsieh ,  Eric Hugh Veach ,  Michael James Boyer Epstein ,  Alexander Lloyd

IPC: G06F17/00 ,  G06F16/23 ,  G06F16/27

Abstract: The subject matter described herein provides techniques to ensure that queries of a distributed database observe a consistent read of the database without locking or logging. In this regard, next-write timestamps uniquely identify a set of write transactions whose updates can be observed by reads. By publishing the next-write timestamps from within an extendable time lease and tracking a “safe timestamp,” the database queries can be executed without logging read operations or blocking future write transactions, and clients issuing the queries at the “safe timestamp” observe a consistent view of the database as it exists on or before that timestamp. Aspects of this disclosure also provide for extensions, done cheaply and without the need for logging, to the range of timestamps at which read transactions can be executed.

公开(公告)号：US20170357674A1

公开(公告)日：2017-12-14

申请号：US15665273

申请日：2017-07-31

Applicant: GOOGLE INC.

Inventor： Wilson Chang-Yi Hsieh ,  Alexander Lloyd ,  Eric Hugh Veach

IPC: G06F17/30

CPC classification number: G06F16/211 ,  G06F16/2322 ,  G06F16/2329

Abstract: The various embodiments described herein include methods, devices, and systems for reading and writing data from a database table. In one aspect, a method of reading and writing data from a database table, includes: (1) initiating a write transaction to write data to a first non-key column of a row of the database table, the database table having a plurality of rows, each row comprising a primary key and a plurality of non-key columns; (2) locking the first non-key column; and (3) in accordance with a determination that the second non-key column is not locked, initiating a read transaction to read data from the second non-key column, where initiation of the read transaction occurs prior to completion of the write transaction.

公开(公告)号：US20140006458A1

公开(公告)日：2014-01-02

申请号：US13909928

申请日：2013-06-04

Applicant: Google Inc.

Inventor： Wilson Cheng-Yi Hsieh ,  Alexander Lloyd ,  Eric Hugh Veach

IPC: G06F17/30

CPC classification number: G06F17/30292 ,  G06F17/30353 ,  G06F17/30356

Abstract: A method reads and writes data from a database table. Each row in the table has a primary key and multiple non-key columns. Each non-key column has one or more column values, and each column value has an associated timestamp that identifies when the column value was stored. The timestamps associated with the column values in each non-key column provide a unique order for the column values. A read transaction is initiated to read from a first non-key column of a first row. A write transaction is in progress that is updating a second non-key column of the first row, where the second non-key column is distinct from the first non-key column. The write transaction holds a lock on the second non-key column of the first row. The method concurrently reads the data from the first non-key column and writes a new column value to the second non-key column.

Abstract translation: 一种方法从数据库表读取和写入数据。 表中的每一行都有一个主键和多个非键列。 每个非键列都有一个或多个列值，每个列值都具有相关联的时间戳记，用于标识列值存储的时间。 与每个非键列中的列值相关联的时间戳为列值提供唯一的顺序。 开始读取事务以从第一行的第一非键列读取。 正在进行正在更新第一行的第二非键列的写事务，其中第二非密钥列与第一非密钥列不同。 写事务在第一行的第二个非键列上保存一个锁。 该方法同时从第一个非密钥列读取数据，并将新的列值写入第二个非密钥列。